Support affiliate patterns (#2027)

## Description:

Patterns have an optional affiliateCode that is associated with an
affiliate/youtuber. These patterns are not shown by default. You can see
them by going to openfront.io/#affiliate=XXX


## Please complete the following:

- [x] I have added screenshots for all UI updates
- [x] I process any text displayed to the user through translateText()
and I've added it to the en.json file
- [x] I have added relevant tests to the test directory
- [x] I confirm I have thoroughly tested these changes and take full
responsibility for any bugs introduced

## Please put your Discord username so you can be contacted if a bug or
regression is found:

evan

src/client/Main.ts

@@ -483,6 +483,13 @@ class Client {
         console.log(`joining lobby ${lobbyId}`);
       }
     }
+    if (decodedHash.startsWith("#affiliate=")) {
+      const affiliateCode = decodedHash.replace("#affiliate=", "");
+      strip();
+      if (affiliateCode) {
+        this.patternsModal.open(affiliateCode);
+      }
+    }
   }
 
   private async handleJoinLobby(event: CustomEvent<JoinLobbyEvent>) {