Fetch retrieves a list of all refs from the remote repository at the given url.

LatestTag attempts to find the highest semver tag from the repository at the given url. Returns the tag and the commit hash of that tag, or an error if no semver tags are found. Tags that can't be parsed as semver are silently ignored.

LatestTagIgnoringPrefix behaves the same as LatestTag, but ignores the given prefix when trying to parse tags as semver. This can be useful if releases are tagged with "release-" or similar.