refactor(rest)!: remove falsy token check (#2949)

* refactor(rest): remove falsy token check
This is in favour for interaction only bots, which still need rest but cannot provide a valid bot token.
If you want to use rest for your normal bot it should be your own responsibility to pass a valid token.

Further more `applicationId` is now a required property since we cannot extract the id from the token anymore.

* forgot to commit that

* fix error

* make appid optional again

* app id throw error if undefined

* fix test

packages/rest/tests/unit/manager.spec.ts

@@ -173,7 +173,7 @@ describe('[rest] manager', () => {
     let time: sinon.SinonFakeTimers
 
     beforeEach(() => {
-      rest = createRestManager({ token: ' ' })
+      rest = createRestManager({ applicationId: 1n })
       time = sinon.useFakeTimers()
     })