multiple expiring system messages (#110, #112)

[mawinter69]

You can now define multiple system messages. Each message can have an expiration time. Messages can be dismissed on a per user basis.

fixes #112 fixes #110

Testing done

Submitter checklist

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

[jonesbusy]

Just updated the plugin, looks I cannot add anymore system message (via JCasC or UI)

jenkins        |        at java.base/java.lang.Thread.run(Unknown Source)
jenkins        | Caused by: java.lang.NullPointerException: Cannot invoke "java.util.Set.removeIf(java.util.function.Predicate)" because the return value of "io.jenkins.plugins.customizable_header.UserHeader.getDismissedMessages()" is null
jenkins        |        at io.jenkins.plugins.customizable_header.CustomHeaderConfiguration.getSystemMessages(CustomHeaderConfiguration.java:143)
jenkins        |        at io.jenkins.plugins.customizable_header.headers.SystemMessageProvider.getSystemMessages(SystemMessageProvider.java:9)
jenkins        |        ... 154 more
jenkins        |  
jenkins        | [2024-06-03T13:34:06.103+0000] [WARNING] hudson.ExpressionFactory2$JexlExpression evaluate # Caught exception evaluating: instance[name] ?: attrs.default in /manage/appearance/. Reason: java.lang.reflect.InvocationTargetException 
jenkins        | java.lang.reflect.InvocationTargetException

[mawinter69]

Just updated the plugin, looks I cannot add anymore system message (via JCasC or UI)

jenkins        |        at java.base/java.lang.Thread.run(Unknown Source)
jenkins        | Caused by: java.lang.NullPointerException: Cannot invoke "java.util.Set.removeIf(java.util.function.Predicate)" because the return value of "io.jenkins.plugins.customizable_header.UserHeader.getDismissedMessages()" is null
jenkins        |        at io.jenkins.plugins.customizable_header.CustomHeaderConfiguration.getSystemMessages(CustomHeaderConfiguration.java:143)
jenkins        |        at io.jenkins.plugins.customizable_header.headers.SystemMessageProvider.getSystemMessages(SystemMessageProvider.java:9)
jenkins        |        ... 154 more
jenkins        |  
jenkins        | [2024-06-03T13:34:06.103+0000] [WARNING] hudson.ExpressionFactory2$JexlExpression evaluate # Caught exception evaluating: instance[name] ?: attrs.default in /manage/appearance/. Reason: java.lang.reflect.InvocationTargetException 
jenkins        | java.lang.reflect.InvocationTargetException

Thanks for reporting, hopefully fixed in version 113.v09524a_dfd80d