RTLCSS Control Directive Fix + Source Maps

[SmushyTaco]

What?

This PR fixes #68364 to allow for the proper use of control directives. It stops the moving of comments and removal of comments from breaking RTLCSS control directives. It also deletes the bundled rtlcss-webpack-plugin in favor of this fork I created which has source map support and is written in TypeScript.

Why?

RTLCSS control directives use comments and if those comments are removed or moved, this will cause this to not function properly. See #68364 for more information.

How?

The issue is addressed by removing all comments only after RTLCSS control directives are processed. This is done by processing cssnano changes through it's proper webpack plugin.

Testing Instructions

Build this SCSS code:

.wp-block-create-block-my-block {
  /*!tedgfdfg*/
  /*!rtl:ignore*/
  text-align: left;
  /*!rtl:remove*/
  background: #CCC;
}

RTLCSS control directives will be correctly applied.

Testing Instructions for Keyboard

Not applicable.

Screenshots or screencast

Not applicable.

[github-actions]

The following accounts have interacted with this PR and/or linked issues. I will continue to update these lists as activity occurs. You can also manually ask me to refresh this list by adding the props-bot label.

If you're merging code through a pull request on GitHub, copy and paste the following into the bottom of the merge commit message.

Co-authored-by: SmushyTaco <smushytaco@git.wordpress.org>
Co-authored-by: Rishit30G <rishit30g@git.wordpress.org>
Co-authored-by: gziolo <gziolo@git.wordpress.org>
Co-authored-by: t-hamano <wildworks@git.wordpress.org>

To understand the WordPress project's expectations around crediting contributors, please review the Contributor Attribution page in the Core Handbook.

[github-actions]

👋 Thanks for your first Pull Request and for helping build the future of Gutenberg and WordPress, @SmushyTaco! In case you missed it, we'd love to have you join us in our Slack community.

If you want to learn more about WordPress development in general, check out the Core Handbook full of helpful information.