dev/core#1684 - Use PSR-4 autoloader instead of PSR-0 for "Civi" namespace

[colemanw]

Overview

This change is to allow underscores in class names, which were being misinterpreted as directory separators.

Before

Classes in the \Civi namespace could not contain underscores.

After

Classes in the \Civi namespace can contain underscores.

Comments

See https://lab.civicrm.org/dev/core/-/issues/1684

[civibot]

(Standard links)

• If this is your first pull-request for CiviCRM, please browse CONTRIBUTING.md for information about the development and testing processes.
• If you are reviewing this pull-request, you may wish to consult the test sites and the Review Standards (long template, short template).

[colemanw]

It seems there are a couple non-compliant names in our test suite, like Civi_AllTests.

[colemanw]

@totten this seems to work fine if we change the Civi directory but leave tests alone.

[totten]

(CiviCRM Review Template WORD-1.2)

• General standards
  • (r-explain) Pass
  • (r-user) Pass
  • (r-doc) Pass
  • (r-run) Pass: Not much to do for this besides running the test suite and doing some click-around on the demo build.
• Developer standards
  • (r-tech) Pass: This is the main consideration, but this doesn't really change the public interface. If you request a class named Civi\Foo, then you still get the same class. I think if it's problematic, we'd see a problem fairly quick from the tests (either on the PR or in the E2E/Ext matrices).
  • (r-code) Pass: Rah-rah PSR-4!
  • (r-maint) Pass
  • (r-test) Pass