fix(example): More responsive firing (#366)

Give the decal the appropriate parent (not top level) and don't use CSGs
for the map.
Fix mouse button `weapon_fire` input not activating due to some keyboard
ghosting issue with Godot. Added an additional `mouse_weapon_fire` to
avoid collision.

---------

Co-authored-by: Tamás Gálffy <ezittgtx@gmail.com>

Author: krazyjakee

examples/multiplayer-fps/multiplayer-fps.tscn

@@ -17,12 +17,11 @@ var pool := NodePool.new()
 
 func _ready():
 	pool.pool_limit = instance_limit
-	pool.spawn_root = self
+	pool.spawn_root = get_tree().root.get_node("multiplayer-fps/Map/StaticBody3D")
 
 	var decal_node: Decal = Decal.new()
 	decal_node.cull_mask = decal_mask
 	decal_node.layers = decal_layer
-	decal_node.top_level = true
 
 	pool.target_node = decal_node
 

examples/multiplayer-fps/scripts/bullethole.gd

@@ -45,7 +45,7 @@ func _gather():
 	movement = Vector3(mx, 0, mz)
 
 	jump = Input.is_action_pressed("move_jump")
-	fire = Input.is_action_pressed("weapon_fire")
+	fire = Input.is_action_pressed("mouse_weapon_fire")
 
 	if override_mouse:
 		look_angle = Vector2.ZERO

examples/multiplayer-fps/scripts/player-input.gd

@@ -80,6 +80,11 @@ move_jump={
 , Object(InputEventJoypadButton,"resource_local_to_scene":false,"resource_name":"","device":-1,"button_index":0,"pressure":0.0,"pressed":true,"script":null)
 ]
 }
+mouse_weapon_fire={
+"deadzone": 0.5,
+"events": [Object(InputEventMouseButton,"resource_local_to_scene":false,"resource_name":"","device":-1,"window_id":0,"alt_pressed":false,"shift_pressed":false,"ctrl_pressed":false,"meta_pressed":false,"button_mask":0,"position":Vector2(0, 0),"global_position":Vector2(0, 0),"factor":1.0,"button_index":1,"canceled":false,"pressed":false,"double_click":false,"script":null)
+]
+}
 weapon_fire={
 "deadzone": 0.5,
 "events": [Object(InputEventMouseButton,"resource_local_to_scene":false,"resource_name":"","device":-1,"window_id":0,"alt_pressed":false,"shift_pressed":false,"ctrl_pressed":false,"meta_pressed":false,"button_mask":0,"position":Vector2(0, 0),"global_position":Vector2(0, 0),"factor":1.0,"button_index":1,"canceled":false,"pressed":false,"double_click":false,"script":null)