Fix/snap version

[Guillaumebeuzeboc]

Hello,

I realized that the version and grade of the foxy snap was not set properly.

Version and grade are set programmatically from the uros-agent part, hence were conflicting with the ones hard coded in the YAML. Also, we need the full git history in the action, so we can get the last tagged version when releasing a non-tagged version (So the name can be tag+git-COMMITHASH)