Refactor files to meet conventions related to scripting.

[tzanon]

Variable and function names, file names, node names, etc.

Scripts in use

• [x] air_barrier.gd
• [x] air_flash.gd
• [x] airburst_arc_rb.gd
• [x] bouncing_bomb.gd
• [x] explosion.gd
• [x] floor_trap.gd
• [x] game_info.gd
• [x] level.gd
• [x] main_menu.gd
• [x] moving_wall.gd
• [x] play_button.gd
• [x] player_airgun.gd
• [x] player_bombshot.gd
• [x] player_explosion.gd
• [x] player_info_ui.gd
• [x] player_manager.gd
• [x] player_select_menu.gd
• [x] player_weapon.gd
• [x] playerRB.gd -> player.gd
• [x] projectile.kb
• [x] results.gd
• [x] (weapon) spawn_point.gd
• [x] wall_spike.gd
• [x] wall_trap.gd
• [x] weapon_spawner.gd
• [x] winner_label.gd
• [x] world_weapon.gd

Placeholder scrips (might need deletion)

• [ ] line_coll_tester.gd
• [ ] proj_sound_test.gd