Main to 3.0; SF 6.0; JDK 17

Initial Commit for Spring Framework 6.0/JDK 17

* PR review comments; build is green.

Fix Spring Data version; fix deprecations

Fix checkstyle

Add mavenCentral() for GE Plugin

.github/workflows/pr-build-workflow.yml

@@ -12,10 +12,10 @@ jobs:
 
     steps:
       - uses: actions/checkout@v2
-      - name: Set up JDK 11
+      - name: Set up JDK 17
         uses: actions/setup-java@v1
         with:
-          java-version: 11
+          java-version: 17
 
       - name: Run Gradle
         uses: burrunan/gradle-cache-action@v1