Improve tagging of docker images

[Huskydog9988]

This creates a number of tags for the docker images, allowing for users to properly follow semver.

To breakdown what tags are created:' nightly, ex nightly (if you run on schedule) {{version}}, ex 4.0.0 {{major}}.{{minor}}, ex 4.0 branch, ex master (when you do on push) Also does a tag for the git sha

See companion pr: https://github.com/modmail-dev/logviewer/pull/71