Fix a typo in Gitlab reporter

[Phyks]

Hi,

There was a typo in the Gitlab reporter, therefore not being able to log errors.

The Gitlab reporter was also expecting a rigid structure (owner/repo) while Gitlab allows for more flexibility (nested subgroups). The second commit should make it possible to use such a nested structure.

Missing changelog entry

[Ndpnt]

Hi @Phyks,
Thanks for the fix and improvement! The code looks good to me. The only thing missing is a changelog entry. I'll take care of adding it, but for reference, you can find the related documentation here.
As for the failed lint check on the commit message, I'll take care of that as well, it looks like our action is not properly configured.

Thanks again for your contribution! :)

[Phyks]

Thanks!