Add adaptive numeric keyboard for color LCD

[onliner10]

Summary

This updates the color LCD NumberEdit touch keyboard from the step-control pad to a direct, adaptive numeric keypad.

The keypad is optimized for touch entry:

• always shows digits, backspace, cursor movement, and OK
• shows +/- only when the edited field can be negative
• shows . only for PREC1 / PREC2 fields
• keeps existing rotary and hardware-key editing semantics intact
• commits typed text through NumberEdit::setValue(), so existing min/max clamping remains authoritative

Fixes #3722.

Screenshots

Positive integer	Decimal field

Signed field	Clamped out-of-range input

Implementation Notes

• Adds raw numeric formatting/parsing helpers to NumberEdit, separate from display strings with prefixes/suffixes/custom handlers.
• Uses a full-screen NumberKeyboard layout for larger finger targets on color LCD radios.
• Adds a small title/value header so the full-screen editor shows what field is being edited without styling the title like the value.
• Keeps custom-display fields on the existing adjustment pad unless they explicitly opt into direct numeric entry.
• Avoids RTTI in firmware builds by using a virtual form-field title hook instead of dynamic_cast.
• Saturates very large typed values before clamping to avoid signed integer overflow.

Testing

• Built the TX16S simulator with the UI harness.
• Exercised the keypad through the UI harness for integer, signed, decimal, fallback/custom-display, and out-of-range clamping scenarios.
• Tested on a TX16S MK2.
• Verified the fork TX16S firmware release workflow builds successfully with strict compiler checks.

[philmoz]

Lvgl has a native numeric keyboard which would be preferable to maintain consistency with the text keyboard.

You can see the numeric keyboard by pressing the SYS key while editing a text field.