Support GitLab syntax about intellij-codeowners

[aarcangeli]

Hi.

I have compared the syntax of gitlab and github and they are very similar.

The only difference is gitlab's sections which can't be parsed by this plugin.

# This rule works
*.xml @octo-org/octocats

[test section name]

# This rule doesn't work
*.cpp @octo-org/octocats

Can we implement this syntax as a variation of the github one instead of creating a complitely different psi tree?

[lukastaegert]

There is a second difference which is that GitLab can have arbitrary nesting for group names, e.g. @octo-org/octocats/wizards/part-time. This is also not supported by this plugin and will prevent the remaining file from being parsed.