Add a hitmarker to grapple hook connects on players to add visual confirmation to a coming bullwhip.

Something I've noticed is that in certain cases when I have a hook kill set ready I'll press the melee button, forgetting that they're hooked and the game will auto-melee anyways, causing me to whiff like a dummy. A hitmarker will also give physical feedback and weight to connecting a mechanism strong enough to fling a human around.