build: add proto generation script for pricesrpc and CI integration

.github/workflows/main.yml

@@ -27,6 +27,16 @@ env:
   GO_VERSION: 1.19.2
 
 jobs:
+   rpc-check:
+     name: RPC check
+     runs-on: ubuntu-latest
+     steps:
+       - name: git checkout
+         uses: actions/checkout@v3
+
+       - name: Generate RPC stubs and check REST annotations
+         run: make rpc-check
+
   ########################
   # lint code
   ########################