Add an `:if_exists` option to `drop_table`

With the old implementation, the bind values were created, and then we
search the attributes for `Relation` objects, and merge them. This
completely ignores the order that the actual `where` clause will use. If
all non-relation where parameters are before the relations, it will
work. However, if we query on both a relation and a value, with the
value coming second, it breaks. The order of the hash should not affect
the final query (especially since hashes being ordered is an
implementation detail)

I'm looking to introduce a `WhereClause` class to handle most of this
logic, and this method will eventually move over to there. However, this
intermediate refactoring should make that easier to do.

Looking through the blame, this logic used to be when we actually
created the bind tuple. My guess is that `nil` couldn't be handled there
at that time. It can, now.

In order to better facilitate refactoring, most places that mutated
`bind_values` have already been removed. One last spot snuck through.
Since we're no longer mutating the array, it also does not need to be
duped in `initialize_copy`.

fix dependency

 Fix wording in AR CHANGELOG about time columns change [ci skip]

 Use force: true options for creating tables in bug templates

fix typo in number_field_tag documentation [ci skip]

If set to `if_exists: true`, it generates a statement like:

    DROP TABLE IF EXISTS posts

This syntax is supported in the popular SQL servers, that is (at least)
SQLite, PostgreSQL, MySQL, Oracle and MS SQL Sever.

Closes #16366.

 - Generally we have to run the bug templates multiple times to get them
   right and it always complains because the posts and comments tables
   already exist due to earlier runs.
 - Using force: true will eliminate this issue.

Fix name_for_action in routing

Use EXEEXT

Remove unused accessor

 Run SQL only if attribute changed for update_attribute method

Should escape regexp wildcard character `.`

`.` is regexp meta character. It should be escape for `assert_match`
correctly.

When an attribute is assigned, we determine if it was already marked as
changed so we can determine if we need to clear the changes, or mark it
as changed. Since this only affects the `attributes_changed_by_setter`
hash, in-place changes are irrelevant to this process. Since calculating
in-place changes can be expensive, we can just skip it here.

I also added a test for the only edge case I could think of that would
be affected by this change.

 - This is based on https://github.com/rails/rails/issues/18400 but
   tackling same issue with update_attribute method instead of update method.

[ci skip] Move a introduction of `Module.nesting`

Use existing constant for joining instead of '_'

remove reference to `Logger` core extensions from guide [ci skip]

nodoc ActionView::ModelNaming module

- Its only used by ActionView internals and not supposed to be used
  through public API.

[ci skip] fix positions of parentheses

Move a introduction of `Module.nesting` to the beginning of sentence.
This change will help reader to try to dump `nesting`.

Eliminate a ruby warning in a test in Action View

This eliminates the warning below:

  actionview/test/template/form_helper_test.rb:913: warning: method redefined; discarding old id_came_from_user?
  actionview/test/template/form_helper_test.rb:104: warning: previous definition of id_came_from_user? was here

 Fixed test for assert_welcome

Thanks @carlosantoniodasilva 💛

Removed documentation of deprecated removed methods