feat(xtask): consolidate CI workflows onto xtask helpers (#542)

- split the xtask crate into structured modules for
  - bindings
  - ci
  - dev
  - util
  - no-std
- Adding commands for
  - ci-release/ci-debug
  - MUSL/no-std
  - per- binding language smoke tests
  - developer tasks (fmt, clippy, pre-commit, pre-push)
- refresh Cargo manifests/locks, binding readmes, and shared FFI helpers so every binding reuses the same preparation steps
- refactor GitHub Actions (release/debug, extensions, CodeQL, clippy, bindings) to call the new xtask commands
- Use rust-cache in ci workflows (microsoft qdk also does this)
- extend README with a contributor workflow section describing how xtask mirrors CI expectations
- update pre-commit and pre-push hooks to use the xtask dev commands

WORKAROUND:
When dotnet is run from an xtask, codeql tracer intercepts it an routes to a nonexistent binary.
Therefore in codeql workflow, xtask is not used for c# and instead dotnet is directly invoked.
Tracked by #545

closes #475

Signed-off-by: Anand Krishnamoorthi <anakrish@microsoft.com>

.github/workflows/test-c-cpp.yml

@@ -19,36 +19,24 @@ jobs:
           fetch-depth: 0
 
       - uses: ./.github/actions/toolchains/rust
+      - name: Cache cargo
+        uses: Swatinem/rust-cache@779680da715d629ac1d338a641029a2f4372abb5 # v2.8.2
+        with:
+          shared-key: ${{ runner.os }}-regorus
+      - name: Fetch dependencies
+        run: cargo fetch --locked
+
+      - name: Fetch FFI crate dependencies
+        run: cargo fetch --locked --manifest-path bindings/ffi/Cargo.toml
 
       - name: Setup gcc, g++, cmake, ninja
         run: sudo apt update && sudo apt install -y gcc g++ cmake ninja-build
 
-      - name: Workaround to ensure that regorus.h is generated
-        run: |
-          cargo fetch
-          cargo build -r --frozen
-        working-directory: ./bindings/ffi
-        
-      - name: Test c binding
-        run: |
-          mkdir bindings/c/build
-          cd bindings/c/build
-          cmake -G Ninja ..
-          ninja
-          ./regorus_test
+      - name: Test C binding via xtask
+        run: cargo xtask test-c --release --frozen
 
-      - name: Test c-nostd binding
-        run: |
-          mkdir bindings/c-nostd/build
-          cd bindings/c-nostd/build
-          cmake -G Ninja ..
-          ninja
-          ./regorus_test
+      - name: Test C (no-std) binding via xtask
+        run: cargo xtask test-c-nostd --release --frozen --skip-ffi
 
-      - name: Test cpp binding
-        run: |
-          mkdir bindings/cpp/build
-          cd bindings/cpp/build
-          cmake -G Ninja ..
-          ninja
-          ./regorus_test
+      - name: Test C++ binding via xtask
+        run: cargo xtask test-cpp --release --frozen --skip-ffi