Change FindTag err when tag not found to NotFound
requested to merge 4366-findtag-returns-an-internal-error-code-when-it-cannot-find-a-specific-tag into master
What
Update the error message to be Not Found rather than Internal when a
tag is not found.
Why
We burn through our error budget when a single user sends a bunch of
requests to tags that don't exist because we classify the error as
Internal, instead it should be NotFound.
Fixes: #4366 (closed)
Edited by Steve Xuereb