feat(vdp): refactor trigger endpoints

[donch1989]

Because

• Previously, we used structpb for our trigger endpoints, which supports JSON but isn’t suitable for binary data.

This commit:

• Refactors the trigger endpoints, separating those that use structpb (which doesn’t support binary data) from those using our custom message for binary data.
• Introduces a gRPC streaming trigger endpoint.
• Reorganizes message structures.

[github-actions]

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Build	Format	Lint	Breaking	Updated (UTC)
✅ passed	✅ passed	✅ passed	✅ passed	Nov 4, 2024, 2:58 AM

[jvallesm]

Suggested change

	// JsonValue represents a JSON value.
	message JsonValue {
	// JSONValue represents a JSON value.
	message JSONValue {

I think we should follow this guide for initialisms.