chore(performance): Refactor EventMetadata deserialization from protobuf

[bruceg]

Summary

The existing code would create an EventMetadata::default() and then fill in the fields coming from the protobuf metadata. Unfortunately, this default creates several non-empty values, notably the source_event_id, which makes that construct take extra time, particularly since the incoming data will (almost?) always already have a source_event_id if the origin is another Vector instance.

While refactoring, I also changed the method to use destructuring to access the fields inside the source value to force the compiler to error if any fields are added later.

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Change Type

• Bug fix
• New feature
• Non-functional (chore, refactoring, docs)
• Performance

Is this a breaking change?

• Yes
• No

Does this PR include user facing changes?

• Yes. Please add a changelog fragment based on our guidelines.
• No. A maintainer will apply the no-changelog label to this PR.

References

Notes

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[thomasqueirozb]

Nice!