Refactor player activites to use item_location

The goal here is to remove all raw indexes to items on the map
or in vehicles as indexes to colonies are unstable while pointers
and iterators are stable.

In this commit ACT_MOVE_ITEMS, ACT_PICKUP, and ACT_WEAR were
refactored to use item_location with significant code cleanup.

src/activity_handlers.cpp

@@ -2562,9 +2562,9 @@ void activity_handlers::pickup_do_turn( player_activity *, player * )
     activity_on_turn_pickup();
 }
 
-void activity_handlers::wear_do_turn( player_activity *, player * )
+void activity_handlers::wear_do_turn( player_activity *act, player *p )
 {
-    activity_on_turn_wear();
+    activity_on_turn_wear( *act, *p );
 }
 
 // This activity opens the menu (it's not meant to queue consumption of items)
@@ -2588,9 +2588,9 @@ void activity_handlers::consume_meds_menu_do_turn( player_activity *, player * )
     g->eat( game_menus::inv::consume_meds );
 }
 
-void activity_handlers::move_items_do_turn( player_activity *, player * )
+void activity_handlers::move_items_do_turn( player_activity *act, player *p )
 {
-    activity_on_turn_move_items();
+    activity_on_turn_move_items( *act, *p );
 }
 
 void activity_handlers::move_loot_do_turn( player_activity *act, player *p )

src/activity_handlers.h

@@ -33,11 +33,10 @@ int butcher_time_to_cut( const player &u, const item &corpse_item, const butcher
 
 // activity_item_handling.cpp
 void activity_on_turn_drop();
-void activity_on_turn_move_items();
+void activity_on_turn_move_items( player_activity &act, player &p );
 void activity_on_turn_move_loot( player_activity &act, player &p );
 void activity_on_turn_pickup();
-void activity_on_turn_wear();
-void activity_on_turn_stash();
+void activity_on_turn_wear( player_activity &act, player &p );
 void try_fuel_fire( player_activity &act, player &p, const bool starting_fire = false );
 
 enum class item_drop_reason {