Change type hints with possible None args or return types to be annotated with Optional - includes commands in core.py and json commands (redis#3610)

* fix(redis-client): change `zrange` num parameter type to `Optional[int]`

* fix(redis-client): normalize optional parameter annotations

Replace all occurrences of Union[T, None] = None and bare T = None
with Optional[T] = None in zrange, _zrange, arrtrim, and other methods
so that type checkers no longer report errors.

* commit message: fix(redis-client): normalize optional parameter annotations and correct arrtrim return type
body: replaced all Union[T, None] = None and bare T = None with Optional[T] = None; changed arrtrim return annotation to Optional[int]

* fix(redis-client): replace Optional[None] with Optional[int] for numeric parameters

Author: kesha1225

CHANGES

@@ -1146,3 +1146,4 @@ incompatible in code using*SCAN commands loops such as
   * Implemented STRLEN
   * Implemented PERSIST
   * Implemented SETRANGE
+  * Changed type annotation of the `num` parameter in `zrange` from `int` to `Optional[int]