Add the configuration option for annotating templates with file names to the generated app

Clarify versioning strategy in maintenance policy

Not all releases are using `X.Y.Z`.

Since 7b391977, `serializable_hash`
allocates fewer objects when options is nil rather than empty.

Fix index options for if_not_exists/if_exists

The `index_exists?` method wasn't very specific so when we added the
`if_not_exists` to `add_index` and `if_exists` to `remove_index` there
were a few cases where behavior was unexpected.

For `add_index` if you added a named index and then added a second index
with the same columns, but a different name, that index would not get
added because `index_exists` was looking only at column named and not at
the exact index name. We fixed `add_index` by moving the `index_exists`
check below `add_index_options` and pass `name` directly to
`index_exists` if there is a `if_not_exists` option.

For `remove_index` if you added a named index and then tried to remove
it with a nil column and a explicit name the index would not get removed
because `index_exists` saw a nil column. We fixed this by only doing the
column check in `index_exists` if `column` is present.
Co-authored-by: NJohn Crepezzi <john.crepezzi@gmail.com>

Add compact and compact! to ActionController::Parameters

Update aws-sdk-s3 dependency

Update active_record_callbacks.md [ci skip]

Co-authored-by: NJonathan Hefner <jonathan@hefner.pro>

Add DidYouMean for ParameterMissing

Journey is a private API that we want to refactor. We need to stop
calling methods directly on it so we're free to change the
implmentation.

Add DidYouMean for HasManyThroughAssociationNotFoundError

whitelist_headers support added in 1.48.0:
https://github.com/aws/aws-sdk-ruby/blob/master/gems/aws-sdk-s3/CHANGELOG.md#1480-2019-08-30

If a parameter isn't found we can suggest similar params:

```
class BooksController < ActionController::Base
  def create
    params.require(:book).require(:name)
    head :ok
  end
end

post :create, params: { magazine: { name: "Mjallo!" } }

param is missing or the value is empty: book
Did you mean?  controller
               action
               magazine

post :create, params: { book: { title: "Mjallo!" } }

param is missing or the value is empty: name
Did you mean?  title

```

If a has_many :through association isn't found we can suggest similar associations:

```
class Author
  has_many :categorizations, -> { }
  has_many :categories, through: :categorizations
  has_many :categorized_posts, through: :categorizations, source: :post
  has_many :category_post_comments, through: :categories, source: :post_comments

  has_many :nothings, through: :kateggorisatons, class_name: "Category"
end

Author.first.nothings

Could not find the association :kateggorisatons in model Author
Did you mean?  categorizations
               categories
               categorized_posts
               category_post_comments
```

- Add the configuration option for annotating templates with file names to the generated app.
- Add `annotate_rendered_view_with_filenames` option to configuring guide.

* Update `fixture_file_upload` documentation to reflect recent changes. [ci skip]

* Friendlier deprecation message for `fixture_file_upload`.

Suggested change now can be copied and pasted into the code without modification.

Fix references in the form builders guide [ci skip]

I caught two references that seemed inconsistent:

1. In section 2.2 Binding a Form to an Object, the code snippet variable was called `form`, but in the bullet points below, it was referenced as `f`.
2. In section 6 Uploading Files, the references to the params hash returned by two different forms was incorrect.

Unify the query values normalization for multiple values

That test requires Marshal is prepended by `MarshalWithAutoloading`.

Use DidYouMean for ActionNotFound

Currently the query values normalization for multiple values is missing
some parts.

Some values are flatten, but others are not flatten.
Some values are compact, but others are not compact.
some values are compact_blank, but others are not compact_blank.

Originally all multiple values should be flatten and compact_blank
before `build_arel`, if it is not ensured which multiple values are
normalized or not, we need to normalize it again carefully and
conservatively in `build_arel`.

To unify the query values normalization for multiple values, ensure the
normalization in `check_if_method_has_arguments!` since all multiple
values should be checked by the method.

* master-sec:
  Check that request is same-origin prior to including CSRF token in XHRs
  HMAC raw CSRF token before masking it, so it cannot be used to reconstruct a per-form token
  activesupport: Avoid Marshal.load on raw cache value in RedisCacheStore
  activesupport: Avoid Marshal.load on raw cache value in MemCacheStore
  Return self when calling #each, #each_pair, and #each_value instead of the raw @parameters hash
  Include Content-Length in signature for ActiveStorage direct upload

If an action isn't found on a controller we can suggest similar actions:

```
The action 'indx' could not be found for SimpleController
Did you mean?  index
```

Fix merging NOT IN clause to behave the same as before

`HomogeneousIn` has changed merging behavior for NOT IN clause from
before. This changes `equality?` to return true only if `type == :in` to
restore the original behavior.

Should not substitute binds when `prepared_statements: true`

Support merging option `:rewhere` to allow mergee side condition to be replaced exactly

Related #39236.

`relation.merge` method sometimes replaces mergee side condition, but
sometimes maintain both conditions unless `relation.rewhere` is used.

It is very hard to predict merging result whether mergee side condition
will be replaced or not.

One existing way is to use `relation.rewhere` for merger side relation,
but it is also hard to predict a relation will be used for `merge` in
advance, except one-time relation for `merge`.

To address that issue, I propose to support merging option `:rewhere`,
to allow mergee side condition to be replaced exactly.

That option will allow non-`rewhere` relation behaves as `rewhere`d
relation.

```ruby
david_and_mary = Author.where(id: david.id..mary.id)

# both conflict conditions exists
david_and_mary.merge(Author.where(id: bob)) # => []

# mergee side condition is replaced by rewhere
david_and_mary.merge(Author.rewhere(id: bob)) # => [bob]

# mergee side condition is replaced by rewhere option
david_and_mary.merge(Author.where(id: bob), rewhere: true) # => [bob]
```

Fix update with dirty locking column to not match latest object accidentally

Fix rename column in bulk alter table for PostgreSQL

PostgreSQL doesn't support rename column operation in bulk alter table.

Fixes #39322.

Related #32163.

We should not identify an object by dirty value. If do so, accidentally
matches latest object even though it is a stale object.