We're still using it in `where_unscoping`, which will require moving
additional logic.

This will make it easy to add `having_clause` and `join_clause` later.

Yes, I know, I called it a factory so I'm basically the worst person
ever who loves Java and worships the Gang of Four.

Bind values are no longer a thing, so this is unnecessary.

This object being a black box, it knows the details of how to merge
itself with another where clause. This removes all references to where
values or bind values in `Relation::Merger`

The way that bind values are currently stored on Relation is a mess.
They can come from `having`, `where`, or `join`. I'm almost certain that
`having` is actually broken, and calling `where` followed by `having`
followed by `where` will completely scramble the binds.

Joins don't actually add the bind parameters to the relation itself, but
instead add it onto an accessor on the arel AST which is undocumented,
and unused in Arel itself. This means that the bind values must always
be accessed as `relation.arel.bind_values + relation.bind_values`.
Anything that doesn't is likely broken (and tons of bugs have come up
for exactly that reason)

The result is that everything dealing with `Relation` instances has to
know far too much about the internals. The binds are split, combined,
and re-stored in non-obvious ways that makes it difficult to change
anything about the internal representation of `bind_values`, and is
extremely prone to bugs.

So the goal is to move a lot of logic off of `Relation`, and into
separate objects. This is not the same as what is currently done with
`JoinDependency`, as `Relation` knows far too much about its internals,
and vice versa. Instead these objects need to be black boxes that can
have their implementations swapped easily.

The end result will be two classes, `WhereClause` and `JoinClause`
(`having` will just re-use `WhereClause`), and there will be a single
method to access the bind values of a `Relation` which will be
implemented as

```
join_clause.binds + where_clause.binds + having_clause.binds
```

This is the first step towards that refactoring, with the internal
representation of where changed, and an intermediate representation of
`where_values` and `bind_values` to let the refactoring take small
steps. These will be removed shortly.

See 4d7a6229 for the reasoning

The structure of `values[:where]` is going to change, with an
intermediate definition of `where_values` to aid the refactoring.
Accessing `values[:where]` directly messes with that, signficantly.

The array wrapping is no longer necessary, since `where_values` will
always return an array.

Fix typos in migration generator comment

Fix a typo "devleopment" => "development"

[ci skip]

fix task description for tmp:create

Add tip for running binstubs on Windows [ci skip]

Add missing options to `datetime_select` [ci skip]

The default command prompt under Windows doesn't run binstubs correctly
while PowerShell needs to find the location of the Ruby interpreter for
it to work properly. Passing the binstubs manually to the interpreter
solves this problem.

This will allow all types which require no additional handling to use
prepared statements. Specifically, this will allow for `true`, `false`,
`Date`, `Time`, and any custom PG type to use prepared statements. This
also revealed another source of nil columns in bind params, and an
inconsistency in their use.

The specific inconsistency comes from a nested query coming from a
through association, where one of the inversed associations is not
bi-directional.

The stop-gap is to simply construct the column at the site it is being
used. This should simply go away on its own once we use `Attribute` to
represent them instead, since we already have all of the information we
need.

This is to help facilitate future refactorings, as the internal
representation is changed. I'm planning on having `where_values` return
an array that's computed on call, which means that mutation will have no
affect. This is the only remaining place that was mutating (tested by
replacing the method with calling `dup`)

Specifically, the issue is relying on `where_unscoping` mutating the
where values. It does not, however, mutate the bind values, which could
cause an error under certain circumstances. This was not exposed by the
tests, since the only place which would have been affected is unscoping
a boolean, which doesn't go through prepared statements. I had a hard
time getting better test coverage to demonstrate the issue.

This in turn, caused `merge` to go through proper logic, and try to
clear out the binds associated with the unscoped relation, which then
exposed a source of `nil` for the columns, as binds weren't expanding
`{ "posts.id" => 1 }` to `{ "posts" => { "id" => 1 } }`. This has been
fixed.

The bulk of `create_binds` needed to be moved to a separate method,
since the dot notation should not be expanded recursively.

I'm pretty sure this removes a subtle quirk that a ton of code in
`Relation::Merger` is working around, and I suspect that code can be
greatly simplified. However, unraveling that rats nest is no small task.

[ci skip] Fix what is pushed to nesting about eval family

Fixed duplicating ActiveModel::Errors#details

Use attribute assignment module logic during ActiveModel initialization.

pretty_print will use #inspect if a subclass redefines it

Extracted attributes assingment from ActiveRecord to ActiveModel

Minor style changes across the board. Changed an alias to an explicit
method declaration, since the alias will not be documented otherwise.

Allows to use it for any object as an includable module.

Given that this was originally added to normalize an error that would
have otherwise come from the database (inconsistently), it's more
natural for us to raise in `type_cast_for_database`, rather than
`type_cast_from_user`. This way, things like numericality validators can
handle it instead if the user chooses to do so. It also fixes an issue
where assigning an out of range value would make it impossible to assign
a new value later.

This fixes several vague issues, none of which were ever directly
reported, so I have no issue number to give. Places it was mentioned
which I can remember:

- https://github.com/thoughtbot/shoulda-matchers/blob/9ba21381d7caf045053a81f32df7de2f49687820/lib/shoulda/matchers/active_model/allow_value_matcher.rb#L261-L263
- https://github.com/rails/rails/issues/18653#issuecomment-71197026