Centralize default user and team preferences. (#5172

Passing the fallback at each callpoint was dumb

server/presenters/publicTeam.ts

@@ -1,9 +1,10 @@
+import { TeamPreference } from "@shared/types";
 import { Team } from "@server/models";
 
 export default function presentPublicTeam(team: Team) {
   return {
     name: team.name,
     avatarUrl: team.avatarUrl,
-    customTheme: team.preferences?.customTheme,
+    customTheme: team.getPreference(TeamPreference.CustomTheme),
   };
 }