Automatic merge from submit-queue (batch tested with PRs 50949, 52155, 52175, 52112, 52188)

Allow watch cache to be disabled per type

Currently setting watch cache size for a given resource does not disable
the watch cache. This commit adds a new `default-watch-cache-size` flag
to map to the existing field, and refactors how watch cache sizes are
calculated to bring all of the code into one place. It also adds debug
logging to startup to allow us to verify watch cache enablement in
production.

Part of #51825 

Will allow watch cache to be disabled selectively.