feature: relay in-game team chat into the team's web chat room

[lukepolo]

Relays in-game say_team into the speaker's private team chat room on the web; all chat still goes to the match room.

• New teamChat game event routes to the MatchTeam room ${matchId}:${lineupId}; an older api has no handler for it and drops it
• A team line never reaches the match room: it is dropped unless the speaker and lineup are well-formed, the lineup is in this match, and the speaker is on it or its coach; a chat event with team fields is dropped too
• Team-room lines reach only the lineup's current roster, not stale presence (a player moved or benched mid-match)
• The current-match payload gains relay_team_chat: true (a JSON boolean), so the plugin only relays to an api that can route team chat
• Team-room notifications become MatchChatMessage (push follows the match_chat preference, off by default); a migration re-types existing rows

Merge/deploy: stacked on #435. Deploy the api before 5stackgg/game-server#196, and merge #451 before this goes live.

Tests: a test fails without each fix: stale team-room presence fan-out, team fields on chat, a lineup from another match, a speaker not on the lineup, the relay_team_chat flag, and the migration's _ escape. The malformed-speaker check only fails on "no Hasura query issued". Based on DEAFCS a986ab1ec