[TaCZ] Half-Life Gunpack

 1.21.3

New guns
- Shock Roach (Opposing Force): fires 5 shock bolts
- Hivehand (Half-Life): left-click lets out hornets that hunt the nearest hostile mob in front of you and turn around off walls. Right-click fires a fast stream of hornets straight ahead. 

Fixes
- Shaders: the physics gun, gravity gun, tau cannon and gluon gun beams now show with Oculus shader packs. So do the RPG's laser dot and rocket trails, the stunstick's sparks and the displacer cannon's flashes.
- Shaders: the glowing shots now show with shader packs too: shock bolts, spores, displacer cannon balls and hornet trails, plus the physics gun's blue glow around a held block.