Fix Events and add TODOs for the next major release

[hafezdivandari]

Related to #1465

• Fixed a bug where "Device Authorization" grant emits wrong events after access / refresh token is issued.
• No event is emitted on "Implicit" grant after an access token is issued, unlike other grants!
  • This can't be fixed without changing the method signature which is a BC breaking change.
  • Added a TODO comment to be fixed on the next major release.
• Added a TODO comment to fix a typo on the argument name of the \League\OAuth2\Server\Repositories\DeviceCodeRepositoryInterface::getDeviceCodeEntityByDeviceCode() method on the next major release: string $deviceCodeEntity -> string $deviceCode