Pierre-Yves David <pierre-yves.david@octobus.net> [Fri, 26 Nov 2021 17:22:14 +0100] rev 48410
extensions: add a default "*" suboptions prefix
This is similar to what we do in other section (e.g. `paths`) and allow to
change the behavior for all extensions.
Sub options on individual extensions overwrite the default settings.
Differential Revision: https://phab.mercurial-scm.org/D11823