Moved and split escoria._ev_left_click_on_item() function into ESCController (#371)

* Moved and split escoria._ev_left_click_on_item() function into ESCController.
Added a boolean in ESCWalkContext to hold whether interact should happen after destination is reached.

Co-authored-by: StraToN <StraToN@users.noreply.github.com>

docs/api/ESCInputsManager.md

@@ -57,6 +57,14 @@ The global id fo the topmost item from the hover_stack
 
 ## Method Descriptions
 
+### register\_core
+
+```gdscript
+func register_core()
+```
+
+Register core signals (from escoria.gd)
+
 ### register\_inventory\_item
 
 ```gdscript