Auto update a release plan when a spec PR is submitted

Auto update a release plan when a spec PR is submitted to update TypeSpec project path, API spec PR URL and package names.

A GitHub agent workflow can be used to auto trigger whenever anew TypeSpec pull request is created in azure-rest-api-specs repo and aw will do the following.
- Identify the list of changed files in the PR and identify the TypeSpec project path.
- If PR updates more than one TypeSpec projects then skip the auto update unless it has only one main project and other projects are shared typespec projects.
- Identify an existing release plan for the TypeSpec project. Update API spec PR URL and package names(parsed using TypeSpec emitter) in the release plan.
- Check if PR updates API version in main.tsp or client.tsp. If PR contains a change to update a new version and if a release plan is missing, then it should create a new release plan with TypeSpec project, PR url, and package names.