Updates after players feedbacks

- fixed assault rifle endless fire without a player click
- fixed 'black squares' glitch during intense shooting
- fixed shotgun impact 'on surface hit' (only 1 of 5+ bullets, for performance reasons)
- performance optimization: texture max sizes reduced for different props
- enemy location small adjustments
- fixed 'Data Cell' dialog trigger position
- fixed player kill NPC in 2d from a far distance (range limited to ~edge of the screen)
- fixed NPS rifle/shotgun firing after AI death
- hide shotgun crosshair between shoots (annoying chaotic move)
- added slight camera shake for shotgun shooting