[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