R1:b34d5bf44ba9

Strip GMail French quote header

Summary: Ref T8199. Add pattern matching for GMail French.

Test Plan:
- Switched Gmail to french.
- Replied to some mail.
- Extracted quoted text header.
- Added and executed unit test.

Reviewers: btrahan

Reviewed By: btrahan

Subscribers: tycho.tatitscheff, epriestley

Maniphest Tasks: T8199

Differential Revision: https://secure.phabricator.com/D12845