Support for git tags/releases

[XVilka]

See radareorg/radare2#17178

Detailed description

When using r2 from non-git (release builds), installing packages can result in build problems. This PR aims to enable r2pm with the ability to pick the right commit from the tagged version from 3rd party repos if available.

Afaik this is done by r2ghidra-dec and r2dec-js, it may be good to define a different tag name than just the r2 version string, otherwise it will confuse users with the version of the decompiler and the version of the r2 required to build. Suggestion is to use r2- as prefix in the 3rd party repos.

Test plan

Get r2-4.4 and type the following command:

$ r2pm install r2ghidra-dec

[qbarrand]

Hi @XVilka, does the source.ref field of the new schema (when source.type=git) solve that problem?

[XVilka]

Yes, that would solve this 👍