discriminatedUnion (#1193)

## Description:

Use the `discriminatedUnion` zod function to more accurately describe
how the `type` field is being used.

## 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
- [x] I understand that submitting code with bugs that could have been
caught through manual testing blocks releases and new features for all
contributors

Co-authored-by: Scott Anderson <662325+scottanderson@users.noreply.github.com>

src/core/Schemas.ts

@@ -372,7 +372,7 @@ export const ServerDesyncSchema = ServerBaseMessageSchema.extend({
   yourHash: z.number().optional(),
 });
 
-export const ServerMessageSchema = z.union([
+export const ServerMessageSchema = z.discriminatedUnion("type", [
   ServerTurnMessageSchema,
   ServerPrestartMessageSchema,
   ServerStartGameMessageSchema,
@@ -428,7 +428,7 @@ export const ClientJoinMessageSchema = z.object({
   flag: SafeString.optional(),
 });
 
-export const ClientMessageSchema = z.union([
+export const ClientMessageSchema = z.discriminatedUnion("type", [
   ClientSendWinnerSchema,
   ClientPingMessageSchema,
   ClientIntentMessageSchema,