Add IsRunning

[Retroeer]

This is just a really simple thing that I've found myself wanting to have, you can check for velocity, or just make your own extension of it, but I feel like this should be a common enough thing to have in base
I will say, wasn't entirely sure where to put the check for it, so feel free to move it around into a different function, also not sure if we should be syncing it, but I haven't come across any use cases where I've needed it, so probably uncommon enough to leave out

(Example use case I just had was adding a running animation to a weapon)

[Retroeer]

Added a check for WishVelocity, if you're holding sprint and not moving you're not exactly sprinting