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