Additional code from xclim

[coxipi]

Pull Request Checklist:

• This PR addresses an already opened issue (for bug fixes / features)
  • This PR fixes #xyz
• (If applicable) Documentation has been added / updated (for bug fixes / features).
• (If applicable) Tests have been added.
• CHANGELOG.rst has been updated (with summary of main changes).
  • Link to issue (:issue:number) and pull request (:pull:number) has been added.

What kind of change does this PR introduce?

Does this PR introduce a breaking change?

Other information:

.pylintrc.toml

removed signature-mutators = ["xclim.sdba.base.map_groups"], should we have this kind of file in xsdba?

[coveralls]

coverage: 76.014% (-2.0%) from 77.992%
when pulling 1e0fc21 on port_changes_from_split
into 8a9d94a on main.