Allow a Release's tag to be changed through the "Edit Release" page

Problem to solve

Changing a Release's Git tag is only possible through the Releases API.

Proposal

Allow existing Releases to be associated to a new or existing Git tag. Currently, the Tag field is disabled when editing a Release on the "Edit Release" page.

The implementation of this feature will be slightly more complicated than editing other Release details as we need to build in the ability to use an existing Git tag or create a new tag on the fly.

Documentation

This page will likely need to be updated with new screenshots and instructions.