FSE: theme data for Global Styles and Templates

[vindl]

We are storing templates and template parts in wp_template and wp_template_parts CPTs respectively. In order to associate them with their corresponding themes, we added wp_theme taxonomy in which the theme stylesheet is saved for each post. (ref)

For storing Global Styles data, we similarly have global_styles CPT, but the corresponding theme info is saved in the post name (wp-global-styles-<theme-stylesheet>). (ref)

Would it make sense to align these approaches for consistency?

cc @nosolosw @mtias @youknowriad

[oandregal]

I've added this to the list of things to do for 5.8 at #20331 (see 3rd wave, theme.json group).

[oandregal]

This has been closed by #31436