Match structure

[ImogenBits]

This just makes the match have a single battle per matchup instead of some number of rounds. The iterated battle wrapper itself then runs some number of rounds internally.

[Benezivas]

Thank you for the PR, could you look into the test that fails in the CI?

======================================================================
ERROR: test_calculate_points_zero_rounds (tests.test_match.Matchtests.test_calculate_points_zero_rounds)
All teams get 0 points if no rounds have been fought.
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/runner/work/algobattle/algobattle/tests/test_match.py", line 48, in test_calculate_points_zero_rounds
    self.assertEqual(match.calculate_points(), {self.team0.name: 0, self.team1.name: 0})
                     ^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/runner/work/algobattle/algobattle/algobattle/match.py", line 95, in calculate_points
    home_res = self.results[home_matchup]
               ~~~~~~~~~~~~^^^^^^^^^^^^^^
KeyError: <exception str() failed>

[ImogenBits]

fixed

[Benezivas]

Thank you for the PR, this can be accepted as-is.