Store Thumbstick, Trackpad etc. data internally in a vec2f.
The knowledge that a binding path ../x and ../y refers to the x and y components of this vec2f
is stored as an INPUT_REDIRECT_VEC2_X_TO_VEC1 or INPUT_REDIRECT_VEC2_Y_TO_VEC enum.
Actions now also store the index of the binding paths it matched to,
e.g. when an action binds ../trackpad/y to an input that provides bindings [../trackpad, ../trackpad/x, ../trackpad/y],
the index 2 is stored.
v2: Clarify preferred binding path index variable
