Block Bindings: Add/update sources for use with Navigation blocks

[Bernhard Reiter]

Block Bindings can be used with the Navigation Link and Navigation Submenu blocks to make sure that the link destination is kept up-to-date based on other attributes, even when the destination changes. Specifically, a Navigation Link or Submenu can point to a given post object or taxonomy term page; these can be specified by a combination of kind (e.g. post-type), type (e.g. page), and id attributes. (The destination can change if e.g. pretty permalinks are used, and a given page's slug is changed.)

The core/post-data source lends itself for the case of post-type links; however, it needs to expose the given post object's link field. For taxonomy terms, a new core/term-data source should be introduced.

Carry over changes to the core/post-data source from ​https://github.com/WordPress/gutenberg/pull/72165.

Trac ticket: https://core.trac.wordpress.org/ticket/64107

Failing CI jobs seem to be unrelated (and present on all recently filed PRs); they seem to be related to the Gutenberg build system (some TypeScript build error specifically?)

I've ​asked in WordPress Slack.

[Bernhard Reiter]

In 60946:

Block Bindings: Add core/term-data source; extend core/post-data.

Add a new core/term-data source to make information about a taxonomy term available for use in Block Bindings.
Additionally, expose a post object's permalink through the core/post-data source.

Props bernhard-reiter, get_dave, jeryj, cbravobernal.
Fixes #64107.