[JENKINS-22087] Add job dsl support for RundeckNotifier plugin

add RundeckContext and modify PublisherContext to support the RundeckNotifier directly in the job dsl
fixing default values in RundeckContext
adding code to correctly collect and join the options and nodeFilters
making sure that the jobId can't be null or empty in the PublisherContext so that it can't be bypassed
fixing test assertion to correctly assert empty value() instead of attributes()
making it explicit where the xml for the RundeckNotifier comes from in the job config xml
make it so options and nodeFilters can be called multiple times just like option and nodeFilter
[JENKINS-22087] Add job dsl support for RundeckNotifier plugin

updating the documentation
[JENKINS-22087] Add job dsl support for RundeckNotifier plugin

updated release notes
[JENKINS-22087] Add job dsl support for RundeckNotifier plugin

updating documentation to be in line with existing documentation format
adding examples of usage
cleanup
Merge branch 'JENKINS-22087'

Conflicts:
	docs/Home.md
Add support for new version of build timeout plugin
Add support for new version of build timeout plugin
Added deprecation warning
Check minimum Plugin Version.
Added extra deprecation warning and extended the migration guide.
cleanup
Merge branch 'timeout'
Gerrit Trigger configuration should honor central gerrit configuration.

Formerly, build status values that where not set where hardcoded in
GerritContext, so even if you defined different default values in your
global gerrit trigger configuration (like CR +2 for sucessful builds),
they would be overriden.

This commit sets default value null and only creates
config entries, when value is not null.