feat: Improve consistency around “match” instead of “game”

[delucis]

This PR addresses #763, updating client and transport implementations to use matchID, matchData, updateMatchID, subscribeMatchData, etc. instead of using “game”.

So far I didn’t include the refactoring of the Storage API as that might require some further consideration, so I’ll await feedback before doing anything about that.

Breaking changes

Clients should now be passed a matchID instead of gameID

import { Client } from 'boardgame.io/react';

const App = Client({ game });

export default () => <App matchID="xyz" />;

import { Client } from 'boardgame.io/client';

const client = Client({
  matchID: 'xyz',
  // ...
});

client.updateMatchID('abc');

React board components will receive matchData instead of gameMetadata

const Board = ({ matchData }) => {
  return <div>{matchData}</div>
};

[nicolodavis]

@delucis: Do you think it's worth shortening matchMetadata to matchData?

I feel like it's unambiguous enough (unlike gameData).

[delucis]

Do you think it's worth shortening matchMetadata to matchData?

Sure, I don’t see why not.

[delucis]

Done in 3cde0a7 & 15bd0ab.