Closes #24190

This reverts commit 3420a145, reversing
changes made to afb66a5a.

Follow up of 03d3f036.

Some of `respond_to?` were replaced to `respond_to_missing?` in 03d3f036.
But the visibility is still public. It should be private.

All indentation was normalized by rubocop auto-correct at 80e66cc4.
But comments was still kept absolute position. This commit aligns
comments with method definitions for consistency.

All indentation was normalized by rubocop auto-correct at 80e66cc4.
But heredocs was still kept absolute position. This commit aligns
heredocs indentation for consistency.

This was almost every case where we are overriding `respond_to?` in a
way that mirrors a parallel implementation of `method_missing`. There is
one remaining case in Active Model that should probably do the same
thing, but had a sufficiently strange implementation that I want to
investigate it separately.

Fixes #26333.

* Documentations and comments about what methods
  `Migration#change` can reverse is out of date.
  For example `change_column_default` is now reversible
  by this [commit](https://github.com/rails/rails/pull/20018).

* Comments about `CommandRecorder` dose not match with Rails Guide.
  For example `add_foreign_key` is listed only on Rails Guide.

This is fix of #11826 which miss to add `disable_extension` to
`ReversibleAndIrreversibleMethods`. So `CommandRecorder#method_missing`
catches `change_column_default` and @delegate's method is called.

This is fix of #20018 which removes `change_column_default` from
array, so `CommandRecorder#method_missing` catches
`change_column_default` and @delegate's method is called.

This PR

* fix this bug
* define `ReversibleAndIrreversibleMethods` const making clear
  which this array means to prevent these miss

Passing `:from` and `:to` to `change_column_default` makes this command
reversible as user has defined its previous state.

So, instead of having the migration command as:

    change_column_default(:posts, :state, "draft")

They can write it as:

    change_column_default(:posts, :state, from: nil, to: "draft")

This used to raise a `IrreversibleMigration` error (since #10437).
However since `remove_index :table, :column` is probably the most basic
use-case we should make it reversible again.

Conflicts:
	activerecord/CHANGELOG.md

This allows to create and remove foreign keys without specifying a column.

Previously when reverting a migration which added a named index it
would instead drop a corresponding index with matching columns but
without a name.

Closes #13623.

  - Earlier, change_table was creating database-agnostic object.
  - After this change, it will create correct object based on current
    database adapter.
  - This will ensure that create_table and change_table will get same objects.
  - This makes update_table_definition method public and nodoc.
  - Fixes #13577 and #13503

If 'enable_extension' is used in a migration's 'change' method, use
'disable_extension' on down migration (and vice-versa).

fixes #10419

Following code should raise  IrreversibleMigration. But the code was
failing since options is an array and not a hash.

def change
  change_table :users do |t|
    t.remove_index [:name, :email]
  end
end

Fix was to check if the options is a Hash before operating on it.

* Fix Migration#reversible by not using `transaction`.

* Adapt mysql adapter to updated api for remove_column

* Update test after aedcd683

[#8267]

[#8267]