PS-Inv used to be exactly the same as QB-Inv so alot of the function calls were shared
This separates them and makes it easier to make changes to support their inventory
Also unified the calls for server side functions into single functions instead of having separate per inventory
Also moves:
- `invImg()` to inventories.lua
- `registerStash()` to stashcontrol.lua
Nothing public uses this yet, but its very similar to QBCore which makes it very for me to support
Nothing special to note, just improves the integration for future ventures into RedM
