Ability to clone EtherealEngine from a user folk/repo and select branches at clone

[HexaField]

We should have an install button that clones the EtherealEngine repo from a user specific version (default to latest tag, with options for previous tags plus all dev commits via search) into a user specified location, runs through the configure workflow and opens the admin panel when done.

[hanzlamateen]

Need to provide user with an ability to list and select branches using some git api call. And then pass the selected branch to configure script as an optional parameter.

https://stackoverflow.com/questions/10649814/get-last-git-tag-from-a-remote-repo-without-cloning