feat: provide state tree proofs

[shuplenkov]

Issue being fixed or feature implemented

Need to provide state tree proofs.

What was done?

Added prove parameter to platform requests, proof parameter to platform responses.

How Has This Been Tested?

Tests

Breaking Changes

No

Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have added or updated relevant unit/integration/functional/e2e tests
• I have made corresponding changes to the documentation

For repository code-owners and collaborators only

• I have assigned this pull request to a milestone

[shumkov]

LGTM! 👍

[Cofresi]

It looks to me as if our proof object doesn't have a version field. Is that true? If yes, then how do we plan to update the proof format, e.g. switching the state tree architecture backend to prefix solution instead of forrest?

[shumkov]

Still good 👍

[shumkov]

@Cofresi protobuf itself provides backward compatibility model. Also, we have versioning in gRPC service name, so if we break it completely we just introduce a new version. Read more https://docs.google.com/document/d/1vq5R-bzz-FdgtBxi1EXTmGVPxoS6qvQ0B-tb7gADs4I/edit