Enable Github Verification and cleanup build scripts

This do the follwoing:
- enable the unified github verification build
- removes obsolete workflows
- move mandatory maven options into the maven.config file

.github/workflows/ci.yml

@@ -0,0 +1,21 @@
+name: Continuous Integration
+concurrency: 
+    group: ${{ github.workflow }}-${{ github.ref }}
+    cancel-in-progress: true
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  check-freeze-period:
+    if: github.event_name == 'pull_request'
+    uses: eclipse-platform/eclipse.platform.releng.aggregator/.github/workflows/verifyFreezePeriod.yml@master
+  check-merge-commits:
+    if: github.event_name == 'pull_request'
+    uses: eclipse-platform/eclipse.platform.releng.aggregator/.github/workflows/checkMergeCommits.yml@master
+  build:
+    uses: eclipse-platform/eclipse.platform.releng.aggregator/.github/workflows/mavenBuild.yml@master
+

.m2/maven.config

@@ -0,0 +1,2 @@
+-Dmaven.compiler.failOnWarning=true
+-Pbuild-individual-bundles

Jenkinsfile

@@ -17,8 +17,8 @@ pipeline {
 			steps {
 				wrap([$class: 'Xvnc', useXauthority: true]) {
 					sh """
-					mvn -U -e -Dmaven.compiler.failOnWarning=true -DskipTests=false -Dmaven.repo.local=$WORKSPACE/.m2/repository \
-						clean verify --batch-mode -Pbuild-individual-bundles -Pbree-libs -Papi-check -Dcompare-version-with-baselines.skip=false
+					mvn -U -e -DskipTests=false -Dmaven.repo.local=$WORKSPACE/.m2/repository \
+						clean verify --batch-mode -Pbree-libs -Papi-check -Dcompare-version-with-baselines.skip=false
 					"""
 				}
 			}