Add new @wordpress/patterns package

[glendaviesnz]

Adds the newly created @wordpress/patterns package. Currently there is duplicated code for adding patterns in post editor (imported from reusable-blocks) and site editor (local modal component), which means any changes need to be applied in two places, so the patterns package was added in order to allow sharing of this code, and also as a means to start slowly deprecating the @wordpress/reusable-blocks package.

## Description

Adds the newly created @wordpress/patterns package. Currently there is duplicated code for adding patterns in post editor (imported from reusable-blocks) and site editor (local modal component), which means any changes need to be applied in two places, so the patterns package was added in order to allow sharing of this code, and also as a means to start slowly deprecating the @wordpress/reusable-blocks package

Trac ticket: https://core.trac.wordpress.org/ticket/59380

## Testing Instructions

This can't be properly tested until the latest GB packages are backported.

• In the post editor add a block and use the Create pattern block menu to create both a synced and an unsynced pattern and make sure both options work as expected
• In the post editor make sure the Detach pattern and Manage patterns options on the block overflow menu work correctly
• In the site editor pattern section use the + at the top of the left navigation to create both a synced and unsynced pattern and make sure both are created as expected
• In the site editor block editor use the Create pattern block menu to create both a synced and an unsynced pattern and make sure both options work as expected and also make sure the Detach pattern and Manage patterns options on the block overflow menu work correctly

## Screenshots or screencast

​https://github.com/WordPress/gutenberg/assets/3629020/d5d7b369-5369-48e3-801c-95d3bdd615f3

[hellofromTonya]

This change is included in #59411 PR ​https://github.com/WordPress/wordpress-develop/pull/5262.

Thinking this ticket can be closed as a duplicate of #59411.

cc @mikachan

[mikachan]

Thinking this ticket can be closed as a duplicate of #59411.

Yes I agree, and can confirm that this change is included in ​https://github.com/WordPress/wordpress-develop/pull/5262.

Closing in favour of #5262

[hellofromTonya]

Duplicate of #59411.

Thank you for confirming @mikachan :)