[NRO-6] Add GitHub workflow for Rust checks: testing, fmt, clippy

Establishes a CI workflow for Rust. It includes running tests, enforcing code
formatting with `cargo fmt`, and linting with `clippy`. This ensures all pushed
code and PRs against main comply with these quality checks.

.github/workflows/rust_checks.yml

@@ -0,0 +1,53 @@
+name: Rust Checks
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - main
+
+jobs:
+  test:
+    name: Run tests
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - name: Install Rust
+      uses: actions-rs/toolchain@v1
+      with:
+        profile: minimal
+        toolchain: stable
+        override: true
+    - name: Run tests
+      run: cargo test --all
+
+  check_format:
+    name: Check format
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - name: Install Rust
+      uses: actions-rs/toolchain@v1
+      with:
+        profile: minimal
+        toolchain: stable
+        override: true
+    - name: Check format
+      run: cargo fmt -- --check
+
+  check_clippy:
+    name: Check clippy
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - name: Install Rust
+      uses: actions-rs/toolchain@v1
+      with:
+        profile: minimal
+        toolchain: stable
+        components: clippy
+        override: true
+    - name: Run Clippy
+      run: cargo clippy -- -D warnings