Follow up to https://jira.mongodb.org/browse/SERVER-89440.

Throughout the codebase where arbitrary error codes are used, for user errors, use one of the user errors introduced in https://jira.mongodb.org/browse/SERVER-89440.

Also, return the UserError label in some fashion in listStreamProcessors.

Make sure the user errors in the past 30 days are covered:

https://splunk.corp.mongodb.com/en-US/app/streams/search?earliest=-30d%40d&latest=now&q=search%20index%3Dmhouse%20source%3Dstreams-spp*%20(c%3DSTREAMS%20%22encountered%20exception%22)%20OR%20%22Error%20starting%20streaming%20job%22%20%7C%20rename%20attr.reason%20as%20errorMsg%20%7C%20rename%20error%20as%20errorMsg%20%7C%20stats%20count%20by%20errorMsg&display.page.search.mode=smart&dispatch.sample_ratio=1&display.page.search.tab=statistics&display.general.type=statistics&sid=1716565660.2660784