[material_ui] Support custom date input formatters via CalendarDelegate

[Mairramer]

This PR adds the keyboardInputFormatters method to CalendarDelegate.

Previously, date input was strictly coupled to MaterialLocalizations. This change allows developers to provide a list of TextInputFormatters via a custom CalendarDelegate to enforce specific input masks (e.g., dd/MM/yyyy) or restrict character entry in date pickers (showDatePicker, showDateRangePicker, and InputDatePickerFormField).

Fixes flutter/flutter#83302
Fixes flutter/flutter#97134
Fixes flutter/flutter#62401
Fixes flutter/flutter#181043
Fixes flutter/flutter#115151
Fixes partially flutter/flutter#150611

Port of flutter/flutter#181105

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