disallow updating to point at empty repo, with an informative message

[LeeMeyer]

Currently if we have already converted a project to version control we get the error A document must have an identifier before it can be tracked. (Parameter 'Id')

It's quite unclear to anyone outside of the config is code team what this actually means, but it boils down to that if a repository is empty and we try to point a config as code project at it, we will expect valid OCL and error out if we do not find it. It's legitimate to point at a repository that contains OCL, but if it's empty the likely fix is that we display a human-readable error message that explains we couldn't find valid OCL in the provided repository, and to either update the repository with valid OCL or point at a repository that contains valid OCL.

[StephenHeise]

Release Note: Improve the error message when the deployment settings file can not be found in the Git repo.

[Octobob]

🎉 The fix for this issue has been released in:

Release stream	Release
2021.3	2021.3.9150
2022.1+	all releases