refactor(examples): add type hints to tic_tac_toe_qlearner

[SH20RAJ]

refactor(examples): add type hints to tic_tac_toe_qlearner

Added type hints to the following functions:

• pretty_board
• command_line_action
• eval_against_random_bots
• main

Cleaned up imports and improved docstrings.
Verified by running the script locally.

[lanctot]

Thanks! (for all the PRs).

On type hints: we didn't have them for a long time because the minimum Python version we supported dated back to before type hints were common. Very happy to add them so long as the minimum version that we supports them (we're currently >= 3.10).

I remember there was a switch for some things like dict vs. typing.Dict and list vs. typing.List but I think we're past that now with >= 3.10.