Make the compiler baseline configuration configurable by properties

Currently the baseline settings are hardcoded (and always override the
platform parent configuration), this extract these into some properties
that can be overridden from the commandline.

This also adjust the Jenkinsfile to use this new way of selectively
disable replace/compare of the baseline in case of building the
compiler-compiler.

See eclipse-platform/eclipse.platform.releng.aggregator#1395

Jenkinsfile

@@ -29,7 +29,7 @@ pipeline {
 					# via configuration/argLine property in pom.xml
 					# export MAVEN_OPTS="-Xmx2G"
 					
-					mvn clean install -f org.eclipse.jdt.core.compiler.batch -DlocalEcjVersion=99.99 -Dmaven.repo.local=$WORKSPACE/.m2/repository
+					mvn clean install -f org.eclipse.jdt.core.compiler.batch -DlocalEcjVersion=99.99 -Dmaven.repo.local=$WORKSPACE/.m2/repository -DcompilerBaselineMode=disable -DcompilerBaselineReplace=none
 					
 					mvn -U clean verify --batch-mode --fail-at-end -Dmaven.repo.local=$WORKSPACE/.m2/repository \
 					-Ptest-on-javase-21 -Pbree-libs -Papi-check \

org.eclipse.jdt.core.compiler.batch/pom.xml

@@ -21,6 +21,8 @@
   <packaging>eclipse-plugin</packaging>
 
   <properties>
+    <compilerBaselineReplace>common</compilerBaselineReplace>
+    <compilerBaselineMode>warn</compilerBaselineMode>
     <defaultSigning-excludeInnerJars>true</defaultSigning-excludeInnerJars>
     <code.ignoredWarnings>-warn:+fieldHiding,-unavoidableGenericProblems</code.ignoredWarnings>
     <localEcjVersion>${project.version}</localEcjVersion>
@@ -76,8 +78,8 @@
         <groupId>org.eclipse.tycho</groupId>
         <artifactId>tycho-p2-plugin</artifactId>
         <configuration>
-          <baselineMode>warn</baselineMode>
-          <baselineReplace>common</baselineReplace>
+          <baselineMode>${compilerBaselineMode}</baselineMode>
+          <baselineReplace>${compilerBaselineReplace}</baselineReplace>
         </configuration>
         <executions>
           <execution>