Fixe base class identification

For previous classes with custom blocks, like SimpleCharacter, you had
to define a method that specified the base class so the picker would
know which blocks to populate itself with.

However, there is a function script.get_instance_base_type() that gets
this automatically from whichever class the script extends. Much nicer
than having to define a function for this every time.

This change also fixes an error when opening the pong game.

Author: wnbaum

addons/block_code/simple_nodes/simple_character/simple_character.gd

@@ -13,10 +13,6 @@ func get_custom_class():
 	return "SimpleCharacter"
 
 
-static func get_base_class():
-	return "CharacterBody2D"
-
-
 static func get_exposed_properties() -> Array[String]:
 	return ["position"]
 

addons/block_code/ui/picker/picker.gd

@@ -25,7 +25,7 @@ func bsd_selected(bsd: BlockScriptData):
 
 	var parent_class: String
 	if found_simple_class_script:
-		parent_class = found_simple_class_script.get_base_class()
+		parent_class = str(found_simple_class_script.get_instance_base_type())
 	else:  # Built in
 		parent_class = bsd.script_inherits