Add support for style states on block instances

[isabel_brison]

​https://github.com/WordPress/gutenberg/pull/76491 adds a new "states" block support, intended to allow styling pseudo states, custom block states such as "current menu item" and specific viewport sizes. This needs adding to core.

Trac ticket: https://core.trac.wordpress.org/ticket/65239

## Use of AI Tools

[audrasjb]

Removing trunk version as this is not going to be shipped with WP 7.0 but in the next releases.

[desrosj]

Since this is an enhancement, there's no first version of WordPress this can be reproduced in. Removing trunk version.

@andrewserong regarding the missing tests, I did omit some that were expecting button width migration changes to already be in place. Those should be added in #12046, so once that one is committed we can add a few more tests if needed.

Ah, perfect. Thanks for clarifying!

[isabel_brison]

In 62453:

Editor: add support for style states on block instances.

Adds a "states" block support that allows styling pseudo states and viewport sizes.

Props isabel_brison, andrewserong, ramonopoly, audrasjb, desrosj.
Fixes #65239.

Just a quick note that this will mean the ​background gradient vs color bug introduced in ​https://github.com/WordPress/gutenberg/pull/76491 will still need a follow-up in core too.

[isabel_brison]

Reopening to add a related bug fix (see ​https://github.com/WordPress/gutenberg/pull/78992)