have sevntu plugin in target platform

That is the most simple way of testing also the sevntu functionality.
Launching a debug runtime with all workspace and target platform plugins
enabled has the sevntu plugin automatically.

config/checkstyle_checks.xml

@@ -402,6 +402,12 @@
  <message key="import.illegal"
  value="Use io.github.classgraph.ClassGraph instead."/>
  </module>
+ <module name="IllegalImport">
+ <property name="illegalPkgs"
+ value="com.github.sevntu"/>
+ <message key="import.illegal"
+ value="The sevntu plugin is only available for debugging. Don''t reference it anywhere in our code."/>
+ </module>
  <module name="ImportControl">
  <property name="id" value="ImportControlMain"/>
  <property name="file" value="${checkstyle.importcontrol.file}"/>

net.sf.eclipsecs.target/net.sf.eclipsecs.target.target

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
 <?pde?>
 <!-- generated with https://github.com/eclipse-cbi/targetplatform-dsl -->
-<target name="Eclipse Checkstyle" sequenceNumber="1711958226">
+<target name="Eclipse Checkstyle" sequenceNumber="1711962228">
  <locations>
  <location includeMode="slicer" includeAllPlatforms="false" includeSource="true" includeConfigurePhase="true" type="InstallableUnit">
  <unit id="org.eclipse.jdt.feature.group" version="3.18.1300.v20220831-1800"/>
@@ -36,6 +36,10 @@
  <unit id="org.objectweb.asm.tree" version="9.3.0.v20220409-0157"/>
  <repository location="https://download.eclipse.org/tools/orbit/downloads/drops/R20220830213456/repository"/>
  </location>
+ <location includeMode="slicer" includeAllPlatforms="false" includeSource="true" includeConfigurePhase="true" type="InstallableUnit">
+ <unit id="com.github.sevntu.checkstyle.checks.feature.feature.group" version="1.44.1"/>
+ <repository location="https://sevntu-checkstyle.github.io/sevntu.checkstyle/update-site/"/>
+ </location>
  <location includeDependencyDepth="none" includeDependencyScopes="compile" includeSource="true" missingManifest="generate" type="Maven" label="SnakeYaml">
  <dependencies>
  <dependency>

net.sf.eclipsecs.target/net.sf.eclipsecs.target.tpd

@@ -45,6 +45,11 @@ location "https://download.eclipse.org/tools/orbit/downloads/drops/R202208302134
  org.objectweb.asm.tree
 }
 
+// include sevntu plugin, so we can test it easily when launching a debug runtime
+location "https://sevntu-checkstyle.github.io/sevntu.checkstyle/update-site/" {
+ com.github.sevntu.checkstyle.checks.feature.feature.group
+}
+
 // If the following part has errors and no syntax highlighting, then please use Help>About>Installation>Installed Software>Target Platform DSL>Uninstall.
 // After restarting please install the current version from the URL in line 1.
 maven ApacheCommons