Add new themes API tags as a hardcoded fallback to the core

[dingo_d]

This ticket is related to meta ticket ​https://meta.trac.wordpress.org/ticket/5212.

Two new tags should be added in order to encourage theme authors to work on FSE features and block patterns.

This ticket adds these two new tags as a hardcoded value to the get_theme_feature_list() function.

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This ticket is related to meta ticket ​https://meta.trac.wordpress.org/ticket/5212.

Two new tags should be added in order to encourage theme authors to work on FSE features and block patterns.

This ticket adds these two new tags as a hardcoded value to the get_theme_feature_list() function.

Trac ticket: https://core.trac.wordpress.org/ticket/50164#ticket

[SergeyBiryukov]

In 47797:

Themes: Add "Block Editor Patterns" and "Full Site Editing" to the list of WordPress theme features.

Follow-up to ​[meta9876].

Props dingo_d.
Fixes #50164. See ​#meta5212.