Add Control Settings to disable or tune down joypad vibration

[manuq]

One common accessibility option in games, usually under "Control Settings", is to disable or tune down vibration. From gameaccessibilityguidelines.com:

Include toggle/slider for any haptics

Currently scenes/game_elements/fx/shaker/shaker.gd is the only script who calls Input.start_joy_vibration().

XP Summary (total 650)

Subdomain	Skill	XP
Engineering: Gameplay & Systems Programming	Problem Solving	150
Engineering: Gameplay & Systems Programming	Creativity & Design Thinking	150
Engineering: Gameplay & Systems Programming	Technical Literacy	150
Game Design: Game Feel & UX	Problem Solving	50
Game Design: Game Feel & UX	Creativity & Design Thinking	75
Game Design: Game Feel & UX	Technical Literacy	75

[wjt]

I remembered that the InputHelper addon has some support for control customisation, and also some API for joypad vibration, but it turns out the latter is very much hardcoded:

threadbare/addons/input_helper/input_helper.gd

Lines 573 to 604 in c6432ae

	#region Rumbling
	func rumble_small(target_device: int = 0) -> void:
	Input.start_joy_vibration(target_device, 0.4, 0, 0.1)
	func rumble_medium(target_device: int = 0) -> void:
	Input.start_joy_vibration(target_device, 0, 0.7, 0.1)
	func rumble_large(target_device: int = 0) -> void:
	Input.start_joy_vibration(target_device, 0, 1, 0.1)
	func start_rumble_small(target_device: int = 0) -> void:
	Input.start_joy_vibration(target_device, 0.4, 0, 0)
	func start_rumble_medium(target_device: int = 0) -> void:
	Input.start_joy_vibration(target_device, 0, 0.7, 0)
	func start_rumble_large(target_device: int = 0) -> void:
	Input.start_joy_vibration(target_device, 0, 1, 0)
	func stop_rumble(target_device: int = 0) -> void:
	Input.stop_joy_vibration(target_device)
	#endregion