Venka Prime extra multiplier gone + some minor QoL changes

[Moise17]

1. With this new melee systems, some melees got something to compensate for losing something unique, like Fragor Prime get some combo multiplier to start with to compensate for the lost extra channeling damage, while Venka Prime didn't get anything to compensate for the lost of the extra combo multiplier.

2. Before the introduction of Phase 1 I could switch my primary/secondary by scrolling down and could equip melee by scrolling up, and now with Phase 2 it kind of forces me to have it bind the switch to melee to something on my keyboard to long press it.