behaviors(hold-tap): Implement quick_tap_ms (TAPPING_FORCE_HOLD)

Tap-and-hold a hold-tap to hold the tap behavior so it can repeat.
After a tap, if the same key is pressed within `quick_tap_ms`, the
tap behavior is always picked.

This is useful for things like `&ht LSHFT BACKSPACE` where holding
the backspace is required.

Implements #288.

app/tests/hold-tap/hold-preferred/behavior_keymap.dtsi

@@ -12,6 +12,7 @@
 			#binding-cells = <2>;
 			flavor = "hold-preferred";
 			tapping_term_ms = <300>;
+			quick_tap_ms = <200>;
 			bindings = <&kp>, <&kp>;
 		};
 	};