fix(tests): quiet down player/matchmaker tests

Use a custom injector with the silent logger to prevent messages from being
logged.
feat(game): add isOver() helper method

This is used to simplify notifying a client that it is their turn, without
emitting the message when the game is over.
fix(game): also emit `game:beginturn` on first turn of game

Also add tests, and refactor tests a bit so that less is being done in beforeEach.
fix(dialog): add end-dialog file

Forgot to add this before, oops.