Issue #3615456: Add complete cacheability metadata to all REST resources

Ten of the thirty resources attached no cache context at all, so their responses were cacheable across languages and across accounts with different access. The three contexts every endpoint varies by are now seeded into the metadata in MyrestResourceBase instead of being repeated per plugin.

Thirteen list cache tags named their bundle as a literal, which after issue 36 is the name the module uses rather than the one the site does; they now resolve through myrest.bundle_map. FrontpageNodeGetResource returned an uncacheable-by -omission empty response when the front page node was missing, so creating the node afterwards never invalidated it.

Adds addCacheableEntities() and addListCacheTags() to the base class.

Co-Authored-By: Claude Opus 5 noreply@anthropic.com

Closes #3615456