feat: json schema for broker api

[dandanlen]

Pull Request

Closes: PRO-xxx

Checklist

Please conduct a thorough self-review before opening the PR.

• I am confident that the code works.
• I have written sufficient tests.
• I have written and tested required migrations.
• I have updated documentation where appropriate.

Summary

Please include a succinct description of the purpose and content of the PR. What problem does it solve, and how? Link issues, discussions, other PRs, and anything else that will help the reviewer.

Non-Breaking changes

If this PR includes non-breaking changes, select the non-breaking label. On merge, CI will automatically cherry-pick the commit to a PR against the release branch.

[codecov]

Codecov Report

Attention: Patch coverage is 2.99401% with 162 lines in your changes missing coverage. Please review.

Project coverage is 71%. Comparing base (41b1edf) to head (32e342f).
Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
utilities/src/with_std/json_schema.rs	0%	72 Missing ⚠️
api/lib/src/lib.rs	0%	23 Missing ⚠️
state-chain/primitives/src/chains/assets.rs	20%	20 Missing ⚠️
state-chain/chains/src/sol/sol_tx_core.rs	0%	15 Missing ⚠️
api/api-json-schema/src/lib.rs	0%	8 Missing ⚠️
foreign-chains/solana/sol-prim/src/macros.rs	0%	6 Missing ⚠️
utilities/src/with_std/rpc.rs	0%	6 Missing ⚠️
state-chain/chains/src/lib.rs	0%	5 Missing ⚠️
state-chain/runtime/src/runtime_apis.rs	0%	4 Missing ⚠️
...ne/src/state_chain_observer/client/base_rpc_api.rs	0%	3 Missing ⚠️

Additional details and impacted files

@@          Coverage Diff           @@
##            main   #5454    +/-   ##
======================================
- Coverage     71%     71%    -0%     
======================================
  Files        507     510     +3     
  Lines      89799   89914   +115     
  Branches   89799   89914   +115     
======================================
- Hits       63908   63849    -59     
- Misses     23265   23439   +174     
  Partials    2626    2626            

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.