Stuff related to parsing engine output

[johndoknjas]

• Adds a private function to read SF output (after a go command), and return it as a list of strings.
• Updates the get_wdl_stats, get_evaluation, and get_top_moves functions to use it. Some cleanup is done in these functions to make the code a little more concise.
• In get_static_eval and _parse_stockfish_version, ensure all of the stockfish engine's stdout output is discarded, after calling _read_lines.

[github-actions[bot]]

Coverage report

The coverage rate went from 93.69% to 96.38% :arrow_up: The branch rate is 93%.

97.77% of new lines are covered.

Diff Coverage details (click to unfold)

### stockfish/models.py `97.77%` of new lines are covered (`96.38%` of the complete file). Missing lines: `711`

[kieferro]

(Just so that there is no misunderstanding: Since this is a WIP I'm assuming you're still working and don't need a review yet. If that should not be the case, just request one :smiley:)

[johndoknjas]

@kieferro Oh yeah, just a few things still left to do for this one. Thx for checking though :)