Handle more pathological branch and tag names (#11843) (#11863)

Handle more pathological branch and tag names (#11843) (#11863)

Backport #11843

It's possible to push quite pathological appearing branch names to gitea
using git push gitea reasonable-branch:refs/heads/-- at which point
large parts of the UI will break. Similarly you can git push origin
reasonable-tag:refs/tags/-- which wil return an error.

This PR fixes the problems these cause. It also changes the code from
creating branches to pushing to ensure that branch restoration has to
pass hooks.

Signed-off-by: Andrew Thornton <art27@cantab.net>
Co-authored-by: techknowlogick <techknowlogick@gitea.io>