ST6RI-849 Initialize Github Actions based build

This change initializes a build based on Github Actions with the following concepts:

 - Only the master branch and pull requests are built
 - All previous build functionality, including the generated library index generation is added
 - Github packages are not updated from a pull request build

Author: ujhelyiz

.github/workflows/build.yml

@@ -0,0 +1,44 @@
+# This workflow will build a Java project with Maven, and cache/restore any dependencies to improve the workflow execution time
+# For more information see: https://docs.github.com/en/actions/automating-builds-and-tests/building-and-testing-java-with-maven
+
+# This workflow uses actions that are not certified by GitHub.
+# They are provided by a third-party and are governed by
+# separate terms of service, privacy policy, and support
+# documentation.
+
+name: Java CI with Maven
+
+on:
+  push:
+    branches: [ "master" ]
+  pull_request:
+    branches: '**'
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v4
+    - name: Set up JDK 17
+      uses: actions/setup-java@v4
+      with:
+        java-version: '17'
+        distribution: 'temurin'
+        cache: maven
+    - name: Build with Maven
+      run: ./mvnw -B clean verify --file pom.xml
+    - name: Publish Test Report
+      uses: mikepenz/action-junit-report@v5
+      if: success() || failure() # always run even if the previous step fails
+      with:
+        report_paths: '**/target/surefire-reports/TEST-*.xml'
+        include_passed: true
+    - name: Verify index generation
+      run: echo $(git diff -- sysml.library/.index.json) | grep -e '^$' || (echo "Library index in the git repository is not up to date. Please re-generate it and push changes to the repository."; exit 1)
+    - name: Publish to Github Packages
+      if: github.event_name != 'pull_request'
+      run: ./mvnw -B deploy -DskipTests=true
+      env:
+        GITHUB_TOKEN: ${{ github.token }} # GITHUB_TOKEN is the default env for the password