(REF) Switch to composer-compile-lib

[totten]

Overview

This is a revision of a change made in the same dev-cycle (#18465). It externalizes some code and makes it easier to use the same techniques in an extension.

Before

• civicrm-core
  • Requires several libraries: scssphp, php-autoprefixer, and compile-plugin
  • Defines a compilation task Civi\Compile\Scss::build.
• civicrm-core:ext/greenwich
  • Uses Civi\Compile\Scss::build

After

• civicrm-core
  • Requires one library (composer-compile-lib) -- which in turn pulls in those others
• civicrm-core:ext/greenwich
  • Uses the shared task CCL\Tasks::scss

Comments

There are a couple upshots of this change:

1. Both core ext's and standalone ext's can use the same helper CCL\Tasks::scss
2. CCL's SCSS helper is a little richer than core's, e.g.
   • The CSS output is written as two files, a larger *.css and a smaller *.min.css
   • Allows another option scss-import-prefixes, which makes it easier to stitch together files from diff places
3. CCL has a few more helpers (which are described in its README).

See also: https://github.com/civicrm/composer-compile-lib

[civibot]

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