Comments UX improvements

[motatoes]

What is this change

Improvements to the backend reporting to add a comment as soon as a webhook is received and this comment will contain a summary of progress. The backend adds the initial comment and it is update by the cli job everytime a job execution completes

Changes introduced by this PR:

• Introduction of a CommentReporter struct to initialize initial comment and keep updating it by backend
• Introduction of DiggerJobSummary to store the list of resources updated, created, deleted by a job and can also contain more items in the future
• Moving shared scheduler models to lib-orchestrator to be shared by both cli and backend
• Modify the set-status endpoint to return the summary of all jobs after it is called
• Modify the cli to report the job plan summary (resources changed) after every change
• Modify the cli to update the comment posted by backend after every job is completed to update it with the summary
• Breaking change: Workflow file now accepts a comment_id parameter and needs to be modified accordingly