Add the ability to manage scheduling of LogBatchPurgeScheduler

[jongpie]

There should be some way within the logBatchPurge LWC to...

• View any scheduled instances of LogBatchPurgeScheduler
• The ability to delete scheduled instances
• The ability to add new scheduled instances, including setting the job name & crown expression

This should all be guarded by a new custom permission & included in the LoggerAdmin permission set