Update test data which doesn't reflect expected usage

Topics call `serialize :content`, which means that the values in the
database should be YAML encoded, and we would only expect to receive
YAML strings to `update_column` and `update_columns`.

if the subdomain wasn't specified, it's the same as if specifying
:subdomain as `true`, so we can default the value to `true` safely.

`normalize_host` already calls `named_host?`, so there is no reason to
test `named_host?` again in the `extract_domain` method.

ActiveRecord::Migration.maintain_test_schema! doesn't work with structure.sql

Conflicts:
	activerecord/CHANGELOG.md

Add unregister_template_handler to prevent leaks.

Conflicts:
	actionview/CHANGELOG.md

Additionally:
* It changes `purge` task on `sqlite3` adapter to recreate database file, to
be consistent with other adapters.
* Adds `purge` step when loading from `schema.rb`

Removed variable shawdowing warning in actionpack url.rb

Before:

/Users/Juan/dev/rails/actionpack/lib/action_dispatch/http/url.rb:95: warning: shadowing outer local variable - port

After:

No warning

Remove unused require

remove unnused method from test

[ci skip] There are 3 caveats to Local Precompilation including 1 config change

[ci skip] Updating argument names in default matcher for compiling files

extract_subdomain always returns a string, and to_param calls to_s on a
string

not 2 caveats with one of them being 2 config changes [ci skip]

irb(main):004:0> /foo/ !~ nil
=> true
irb(main):005:0> /foo/ !~ 'bar'
=> true
irb(main):006:0> /foo/ !~ 'foo'
=> false

to match arguments used in sprockets-rails [ci skip]

remove the default parameter since the methods are always called with a
parameter

Pluck should work with columns of the same name from different tables

The column name given by the adapter doesn't include the table
namespace, so going through the hashed version of the result set causes
overridden keys.

Fixes #15649

This reverts commit 79469b4b.

Revert "No need to require to_param, it is already required in to_query.rb"

This reverts commits ccdd9766
and d697ee14.

Reason by @jeremy: These requires are not for implementation dependency.
They ensure that requiring array conversions provides to_query, to_param,
and other array conversion behaviors.

The fact that to_query is implemented in terms of to_param is just a
coincidence. If to_query removed its to_param require, then someone
requiring array conversions would no longer have to_param available.

This change removes these intentional dependencies on to_param in favor
of implementation side effects—an undesirable move that's susceptible to
regression.

remove unnecssary require of `to_param`, as `to_query` is already require `to_param`

remove warnings

warning: assigned but unused variable - scope_called, path and strexp

We're not longer using `ipaddr` in schema dumper