Sportsdataverse

- Minor changes to cfb_pbp functions to improve WP calculation and player parsing.

- Switched most under the hood dataframe operations to use the python `polars` library and many functions now have a parameter `return_as_pandas` which defaults to `False` but can be set to `True` to return a pandas dataframe instead of a polars dataframe. This is a **breaking change.**
- Added `**kwargs` which pass arguments to the `dl_utils.download()` function, including `headers`, `proxy`, `timeout` (default 30s), `num_retries` (default = 15), `logger` (default = None)
- Function `espn_cfb_game_rosters()` added.
- Function `espn_nba_game_rosters()` added.
- Function `espn_nfl_game_rosters()` added.
- Function `espn_nhl_game_rosters()` added.
- Function `espn_wbb_game_rosters()` added.
- Function `espn_wnba_game_rosters()` added.
- Function `load_cfb_betting_lines()` added (only 2006 through 2019).

- Reconfigured some imports
- Improved compliance with pandas upgrades
- Updated loader locations to use sportsdataverse-data releases and nflverse releases
- Flattened the returned results somewhat for "sportsdataverse.cfb.espn_cfb_schedule()" functions, but also now including some nested data frame and list columns

- Added ondays parameter to ESPN calendar functions
- Renamed "sportsdataverse.cfb.cfb_teams()" to "sportsdataverse.cfb.espn_cfb_teams()" to avoid an edge case issue when running the function.

- Added MLBAM API functionality to the sportsdataverse-py package. For more information on how to use these new functions, refer to the docs.
- Fixed a bug where the "sportsdataverse.nfl.load_nfl_schedule()" function would cause a 404 error when run.
- For functions where multiple files are loaded in, progress bars have been added to indicate how far along the sportsdataverse-py package is in completing its task(s).
- Renamed "sportsdataverse.cfb.cfb_teams()" to "sportsdataverse.cfb.get_cfb_teams()" to avoid an edge case issue when running the function.

- Refactor schedule and teams functions for all existing leagues.
- Created more robust home/away mappings to simplify assignment.