schema_registry: Automatically support google well-known types

[BenPope]

Support google well known types.

Fix #7189 Fix #5771

TODO:

• Add probably most of these: https://github.com/googleapis/googleapis/tree/master/google/type
• Consider the other missing types.
• Maybe make it more efficient by adding all these types as a one-off. If I recall, though, the version of the DescriptorPool that allows a backing store has a std::mutex, so we can't use that.

Signed-off-by: Ben Pope [email protected]

Backports Required

• [ ] none - not a bug fix
• [ ] none - issue does not exist in previous branches
• [ ] none - papercut/not impactful enough to backport
• [x] v22.3.x
• [x] v22.2.x
• [x] v22.1.x

UX Changes

Release Notes