Refactored workflows

- Improve workflow names
- Split execution testing from cache testing

.github/workflows/integTest-execution.yml

@@ -0,0 +1,42 @@
+name: Test Gradle execution
+
+on:
+  pull_request:
+  push:
+  workflow_dispatch:
+
+env:
+  CACHE_KEY_PREFIX: ${{github.workflow}}#${{github.run_number}}-
+
+jobs:   
+  # Tests for executing with different Gradle versions. 
+  # Each build verifies that it is executed with the expected Gradle version.
+  gradle-execution:
+    strategy:
+      matrix:
+        os: [ubuntu-latest, macos-latest, windows-latest]
+        include:
+          - os: windows-latest
+            script-suffix: '.bat'
+    runs-on: ${{ matrix.os }}
+    steps:
+    - name: Checkout sources
+      uses: actions/checkout@v2
+    - name: Test use defined Gradle version
+      uses: ./
+      with:
+        gradle-version: 6.9
+        build-root-directory: __tests__/samples/no-wrapper
+        arguments: help -DgradleVersionCheck=6.9
+    - name: Test use Gradle version alias
+      uses: ./
+      with:
+        gradle-version: release-candidate
+        build-root-directory: __tests__/samples/no-wrapper
+        arguments: help -DgradleVersionCheck=7.2
+    - name: Test use defined Gradle executable
+      uses: ./
+      with:
+        gradle-executable: __tests__/samples/basic/gradlew${{ matrix.script-suffix }}
+        build-root-directory: __tests__/samples/no-wrapper
+        arguments: help -DgradleVersionCheck=7.1.1