Backport: Templates perf: resolve patterns server side

[ellatrix]

Original PR: ​https://github.com/WordPress/gutenberg/pull/60349

To prevent pattern fetching on editor load, and replacing pattern blocks on render, resolve the pattern block server side. This resulted in a 6% performance improvement for pattern loading in the Gutenberg plugin.

Trac ticket: https://core.trac.wordpress.org/ticket/61228

Closing and reopening since I didn't make this PR from my fork.

Trac ticket: https://core.trac.wordpress.org/ticket/61228

To test: check the patterns endpoint and search for wp:pattern. There should be 0 results.

@anton-vlasenko Yes, it needs unit tests, but I'm unfamiliar with unit test in PHP and core. Would you be able to assist?

@anton-vlasenko Yes, it needs unit tests, but I'm unfamiliar with unit test in PHP and core. Would you be able to assist?

Yes, I can look into it.

By the way, I noticed that the $inner_content function argument might not be necessary because it seems to only pass information that's already in the $blocks function argument.

I inline commented on that, it is necessary to change because serialise will break if it's not adjusted

@anton-vlasenko Added unit tests

[ellatrix]

In 58303:

Editor: resolve patterns server side.

See ​https://github.com/WordPress/gutenberg/pull/60349.
See ​https://github.com/WordPress/gutenberg/pull/61757.
See ​https://github.com/WordPress/wordpress-develop/pull/6673.

Fixes #61228.

Props ellatrix, antonvlasenko.

[desrosj]

In 58408:

Coding Standards: Apply changes after running composer format.

This applies several formatting related changes made while running composer format.

Follow up to [55720], [58171], [58271], [58282], [58283], [58292], [58299], [58303], [58332].
See #51857, #60719, #60895, #61021, #61118, #61228, #61276, #61324.