Menu: Typeahead now accounts for leading whitespace

Fixes #10649
Closes gh-1356
Datepicker: Fix French locale

Thanks Jérémy M

Fixes #10651
Closes gh-1357
Datepicker: Fix test for French locale

Ref #10651
Slider: Don't allow a slider's value to exceed its max

Fixes #9376
Closes gh-1016