Improve JSON-RPC CI, no need to build things multiple times

.github/workflows/jsonrpc.yml

@@ -0,0 +1,45 @@
+name: JSON-RPC API Test
+
+on:
+  push:
+    branches: [master]
+  pull_request:
+    branches: [master]
+
+env:
+  CARGO_TERM_COLOR: always
+
+jobs:
+  build_and_test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Use Node.js 16.x
+        uses: actions/setup-node@v1
+        with:
+          node-version: 16.x
+      - uses: actions-rs/toolchain@v1
+        with:
+          profile: minimal
+          toolchain: stable
+          override: true
+      - name: Add Rust cache
+        uses: Swatinem/rust-cache@v1.3.0
+      - name: npm install
+        run: |
+          cd deltachat-jsonrpc/typescript
+          npm install
+      - name: Build TypeScript, run Rust tests, generate bindings
+        run: |
+          cd deltachat-jsonrpc/typescript
+          npm run build
+      - name: Run integration tests
+        run: |
+          cd deltachat-jsonrpc/typescript
+          npm run test
+        env:
+          DCC_NEW_TMP_EMAIL: ${{ secrets.DCC_NEW_TMP_EMAIL }}
+      - name: Run linter
+        run: |
+          cd deltachat-jsonrpc/typescript
+          npm run prettier:check