moved all build related code rom global to buildmanger

Scripts/build_manager.gd

@@ -7,6 +7,15 @@ extends Node
 
 signal build_object_selected
 
+signal exit_build_mode
+signal enter_build_mode
+
+signal preview_created
+signal preview_destroyed
+
+signal object_placed(build_postion)
+
+var build_mode: bool = false
 
 var selected_object_id: int
 var is_object_selected: bool
@@ -18,6 +27,15 @@ func _ready() -> void:
 	is_object_selected = false
 	build_object_selected.connect(_on_object_selected)
 
+func _input(event: InputEvent) -> void:
+	if event.is_action_released("enter_build_mode"):
+		if build_mode:
+			exit_build_mode.emit()
+			build_mode = false
+		else:
+			enter_build_mode.emit()
+			build_mode = true
+
 func get_preview_object():
 	var selected_object
 	match selected_object_id: