Add taxonomy for user created patterns

[glendaviesnz]

The Gutenberg plugin added a taxonomy to allow users to categorise their own patterns (​https://github.com/WordPress/gutenberg/pull/53163), so this needs to be merged for the 6.4 release.

## Description

Adds a custom taxonomy wp_pattern_category to allow users to assign categories to their custom patterns.

​Gutenberg PR .

Trac ticket: [](https://core.trac.wordpress.org/ticket/59379)

## Testing Instructions

• Go to /wp-admin/edit.php?post_type=wp_block and add a new pattern
• Make sure the Category option appears in the right settings panel and that you can add new categories

## Screenshots or screencast

​https://github.com/WordPress/gutenberg/assets/3629020/63895ddc-415a-4fea-ac7a-177813d138a4

@glendaviesnz, do you mind including changes from ​https://github.com/WordPress/gutenberg/pull/54567 here as well?

Thank you, @glendaviesnz!

@glendaviesnz, do you mind including changes from ​WordPress/gutenberg#54567 here as well?

Done @Mamaduka

@tellthemachines the remaining test failures don't seem to be related this PR but I don't have permissions to restart them - are you able to rerun the failed jobs please?

@glendaviesnz thanks for sorting the issue out! I've restarted the e2e tests but they've been failing often on PR branches so it's not really a concern 🤷 as long as all the PHP tests pass we're good.

[isabel_brison]

In 56642:

Taxonomy: add taxonomy for user pattern categories.

Adds a wp_pattern_category taxonomy linked to the wp-block object.

Props glendaviesnz, kebbet, desrosj, mamaduka.
Fixes #59379.

Committed in r56642.