fix: Ensure event annotations is included in compile-time protobuf descriptors

[SanjayVas]

A FileDescriptor that is a compile-time dependency is not considered the same as the FileDescriptor loaded at run-time from a FileDescriptorSet for the same file. This ensures that the FileDescriptor for event_annotations.proto known at compile-time is used instead of one that's possibly loaded from the --event-message-descriptor-set option.

[wfa-reviewable]

This change is 

[SanjayVas]

This is intended to resolve #1934. For reasons discussed offline, there is no good way to test this in the Halo codebase without significant refactoring to ensure that the event message type used for the test is not a compile-time dependency¹. Therefore testing/verification is reliant on operators that use this feature, e.g. Origin.

Footnotes

1. More accurately, that no build target that includes the EDP simulator also transitively includes the event and/or metadata types used for testing ↩

[stevenwarejones]

Reviewed 4 of 4 files at r1, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @SanjayVas)