Add an option to change analogue stick sensitivity

[Hecklezz]

Currently, there is no way to adjust the sensitivity of analogue sticks for controllers.
This is convenient for two reasons-

1. Some people might want to reach maximum character movement speed, or camera movement speed, without having to push their stick/s to their maximum to achieve
2. Some controllers can become slightly defective or are slightly less sensitive resulting in sometimes not even 100% range of the analogue sticks being achieved even when the stick/s are pushed to their maximum.

Other programs support this feature, for example-

1. PCSX2 supports this and defaults to 133% analogue stick sensitivity
2. Steam supports this and has the option to set each analogue stick to "aggressive" so they reach their 100% output faster than usual.