JENKINS-65892 Support macro tokens in github context label

[gjabouley-invn]

This is another attempt to address JENKINS-65892.

Initial change is in #5, credits to @akomakom.

As i did not know how to rebase @akomakom repo, i just cherry-picked its change over the latest master of main repo.

Note that although change is quite simple, i was not able to test the feature, as i don't have a testing environnement available which includes a working GitHub setup...

Submitter checklist

Beta Give feedback

1. Make sure you are opening from a topic/feature/bugfix branch (right side) and not your main branch!
2. Ensure that the pull request title represents the desired changelog entry
3. Please describe what you did
4. Link to relevant issues in GitHub or Jira
5. Link to relevant pull requests, esp. upstream and downstream changes
6. Ensure you have provided tests - that demonstrates feature works or fixes the issue

[gjabouley-invn]

Was able to test it today, tokens are properly replaced 👍

Following output will show twice in build log, not sure it is worth printing actually:
Github Custom Notification Context: Expanded token macro from 'jenkins/${JOB_BASE_NAME}' to 'jenkins/feature%2Ftest_check'

In case of error (variable does not exist), the following is printed in build log:

Github Custom Notification Context: Unable to expand GitHub Notification context macro 'jenkins/${BERFEZGESZ}'ERROR: Github Custom Notification Context: Unable to expand GitHub Notification context macro 'jenkins/${BERFEZGESZ}'
org.jenkinsci.plugins.tokenmacro.MacroEvaluationException: Error processing tokens
	at org.jenkinsci.plugins.tokenmacro.Parser.parse(Parser.java:97)
	at org.jenkinsci.plugins.tokenmacro.Parser.process(Parser.java:75)
	at org.jenkinsci.plugins.tokenmacro.Parser.process(Parser.java:68)
	at org.jenkinsci.plugins.tokenmacro.TokenMacro.expand(TokenMacro.java:196)
	at org.jenkinsci.plugins.tokenmacro.TokenMacro.expandAll(TokenMacro.java:234)
	at org.jenkinsci.plugins.tokenmacro.TokenMacro.expandAll(TokenMacro.java:204)
	at org.jenkinsci.plugins.githubScmTraitNotificationContext.NotificationContextTrait$CustomContextNotificationStrategy.buildContext(NotificationContextTrait.java:127)
	at org.jenkinsci.plugins.githubScmTraitNotificationContext.NotificationContextTrait$CustomContextNotificationStrategy.buildNotification(NotificationContextTrait.java:161)
	at org.jenkinsci.plugins.githubScmTraitNotificationContext.NotificationContextTrait$CustomContextNotificationStrategy.notifications(NotificationContextTrait.java:180)
	at org.jenkinsci.plugins.github_branch_source.GitHubBuildStatusNotification.createBuildCommitStatus(GitHubBuildStatusNotification.java:92)
	at org.jenkinsci.plugins.github_branch_source.GitHubBuildStatusNotification$JobCompletedListener.onCompleted(GitHubBuildStatusNotification.java:333)
	at hudson.model.listeners.RunListener.lambda$fireCompleted$0(RunListener.java:207)
	at jenkins.util.Listeners.lambda$notify$0(Listeners.java:59)
	at jenkins.util.Listeners.notify(Listeners.java:67)
	at hudson.model.listeners.RunListener.fireCompleted(RunListener.java:205)
	at org.jenkinsci.plugins.workflow.job.WorkflowRun.finish(WorkflowRun.java:645)
	at org.jenkinsci.plugins.workflow.job.WorkflowRun$GraphL.onNewHead(WorkflowRun.java:1068)
	at org.jenkinsci.plugins.workflow.cps.CpsFlowExecution.notifyListeners(CpsFlowExecution.java:1500)
	at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup$3.run(CpsThreadGroup.java:512)
	at org.jenkinsci.plugins.workflow.cps.CpsVmExecutorService$1.run(CpsVmExecutorService.java:41)
	at hudson.remoting.SingleLaneExecutorService$1.run(SingleLaneExecutorService.java:139)
	at jenkins.util.ContextResettingExecutorService$1.run(ContextResettingExecutorService.java:28)
	at jenkins.security.ImpersonatingExecutorService$1.run(ImpersonatingExecutorService.java:68)
	at jenkins.util.ErrorLoggingExecutorService.lambda$wrap$0(ErrorLoggingExecutorService.java:51)
	at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
	at java.base/java.lang.Thread.run(Thread.java:829)
Caused by: org.jenkinsci.plugins.tokenmacro.MacroEvaluationException: Unrecognized macro 'BERFEZGESZ' in 'jenkins/${BERFEZGESZ}'
	at org.jenkinsci.plugins.tokenmacro.Parser.processToken(Parser.java:492)
	at org.jenkinsci.plugins.tokenmacro.Parser.parseDelimitedToken(Parser.java:178)
	at org.jenkinsci.plugins.tokenmacro.Parser.parseToken(Parser.java:111)
	at org.jenkinsci.plugins.tokenmacro.Parser.parse(Parser.java:87)
	... 28 more

and a commit check with raw string is created: