Add Unified Admin Color Schemes module skeleton

[getdave]

Adds a new module skeleton to provide a starting point for all code required for the admin color scheme unification on Dotcom.

Changes proposed in this Pull Request:

• Adds new module unified-admin-color-schemes.

Jetpack product discussion

Automattic/wp-calypso#45675

Does this pull request change what data or activity we track or use?

Nope

Testing instructions:

• Checkout PR.
• Add some debugging to the uacs_setup_admin function.
• Check the debugging is run.

Proposed changelog entry for your changes:

• Adds unified-admin-color-schemes module.

[jetpackbot]

	Fails
🚫	Please add these new PHP files to PHPCS required list in bin/phpcs-requirelist.js for automatic linting: modules/unified-admin-color-schemes.php

E2E results is available here (for debugging purposes): https://jetpack-e2e-dashboard.herokuapp.com/pr-17750

This is an automated check which relies on PULL_REQUEST_TEMPLATE. We encourage you to follow that template as it helps Jetpack maintainers do their job. If you think 'Testing instructions' or 'Proposed changelog entry' are not needed for your PR - please explain why you think so. Thanks for cooperation 🤖

Generated by 🚫 dangerJS against fba352d

[marekhrabe]

This works okay as described. Let's add the file to the list as the bot comment above suggests.

The place for the module looks good to me but for this case, I'd rather have a secondary check from somebody in the crew, just to make sure we land it appropriately.

My other note is about the uacs shorthand. These always seem cryptic to me and I'm not sure whether that's a built-in system name or something we came up with. Would it make sense to write those words out or do something like jetpack_color_schemes instead? I'll leave this up to you, since I don't think it breaks any rule.

[jeherve]

The place for the module looks good to me but for this case, I'd rather have a secondary check from somebody in the crew, just to make sure we land it appropriately.

Discussion: p1604926678074100-slack-CJS75TX3R

My personal preference would be for us to expand the existing masterbar module, which already gets preferential treatment on Atomic sites, to include all those UI tweaks we'll be making for Atomic sites.

As part of the changes, we could even rename the module; as long as the module slug (the entry point's file name, modules/masterbar.php, remains the same, we won't lose anything.

My other note is about the uacs shorthand. These always seem cryptic to me and I'm not sure whether that's a built-in system name or something we came up with.

I think it'd be okay, and more readable to switch to a namespace that better describes this?

[obenland]

See #17629 for a first attempt at adding to the masterbar module

[getdave]

Note that if we proceed with this approach we'll want to structure it as a class similar to how we'd done in #17762. We could also consider namespacing.

[obenland]

Fixed in #17762