Core: Cleanup: Replace direct calling of dunder methods on objects (#4584)

Calling the dunder method has to:
1. Look up the dunder method for that object/class
2. Bind a new method instance to the object instance
3. Call the method with its arguments
4. Run the appropriate operation on the object

Whereas running the appropriate operation on the object from the start
skips straight to step 4.

Region.Register.__getitem__ is called a lot without #4583. In that case,
generation of 10 template Blasphemous yamls with
`--skip_output --seed 1` and progression balancing disabled went from
19.0s to 18.8s (1.3% reduction in generation duration).

From profiling with `timeit`
```py
        def __getitem__(self, index: int) -> Location:
            return self._list[index]
```
appears to be about twice as fast as the old code:
```py
        def __getitem__(self, index: int) -> Location:
            return self._list.__getitem__(index)
```

Besides this, there is not expected to be any noticeable difference in
performance, and there is not expected to be any difference in semantics
with these changes.

Co-authored-by: NewSoupVi <57900059+NewSoupVi@users.noreply.github.com>

CommonClient.py

@@ -211,7 +211,7 @@ class CommonContext:
             return iter(self._game_store)
 
         def __repr__(self) -> str:
-            return self._game_store.__repr__()
+            return repr(self._game_store)
 
         def lookup_in_game(self, code: int, game_name: typing.Optional[str] = None) -> str:
             """Returns the name for an item/location id in the context of a specific game or own game if `game` is