feat: Add the ability to .select() custom fields by their field handle

[khalwat]

Description

Currently, if you want to do something like:

    {% set result = craft.entries.section('blog').select(['plainText']).asArray().all() %}

...where plainText is a custom field handle, it won't work, because field columns in the content table have a prefix, and sometimes a suffix as well.

This makes it nigh impossible to do the above code from Twig, because you need to call ElementHelper::fieldColumnFromField() on the field handle to get the column, and ElementHelper isn't directly available in Twig.

This makes using .select() for optimal queries somewhat limited via Twig, as often what you care about is custom fields.

This PR leverages the existing yii\db\Query::normalizeSelect() method to swap in the real column name for custom fields (after Yii2 has already normalized them to an array), so the above "just works" and returns something like this:

[
    0 => [
        'plainText' => 'Some plain text'
    ]
]

It'll also "just work" via PHP as well. It only affects ElementQuery's, and only when .select() is used, so it should be pretty unintrusive.

[brandonkelly]

Implemented the same feature but in a different way via #11800, for Craft 4.3 🎉