Add unit test for non-existing block-styles registration

[aristath]

Adds PHPUnit test for https://core.trac.wordpress.org/changeset/54155

Trac ticket: https://core.trac.wordpress.org/ticket/56664

[mukesh27]

@aristath in which case we get result for generate_block_asset_handle( $metadata['name'], $field_name, $index )?

Do we need the unit test for this changes?

[aristath]

The issue was introduced in ​https://github.com/WordPress/wordpress-develop/commit/3381f05fa241daf172d6c1c893fd25959c3b0656#diff-8c99af92e4ec0fdb307ddd9b42be1e1ef1efe4a9f31287c23f346244dddd1ce9R227, where wp_normalize_path() was added on line 227 a few days ago.

Do we need the unit test for this changes?

We should probably add one to prevent something like this from happening in the future. However, writing a test for this one will be a bit more complicated than the existing tests for this function. I'll work on it, but in the meantime, the lack of a future-proofing test should not be considered a blocker for this bugfix.

[aristath]

Turns out, the test for this was simpler than I initially believed. Added the test 👍

[mukesh27]

Thanks for the unit test. The PR has some conflict that must be resolved.

[aristath]

😂 Looks like this was just fixed a few minutes ago in https://core.trac.wordpress.org/changeset/54155
However, that patch does not include a unit-test. I'll change the subject of this ticket, remove the changes in blocks.php from my patch and leave only the PHPUnit test as it should still be relevant with the patch that was pushed.

[audrasjb]

Self assigning for commit.

[audrasjb]

In 54472:

Build/Test Tools: Add unit test for non-existing block-styles registration.

Follow-up to [54155].

Props aristath, mukesh27.
Fixes #56664.

Committed in https://core.trac.wordpress.org/changeset/54472