feat(handlers): add getGatewayBot() & getApplicationInformation() (#428)

* feat(handlers): add getGatewayBot()

* refactor(bot): use getGatewayBot() to get gateway data

* feat(handlers): add getApplicationInformation

* add(handlers): getApplicationInformation jsdoc

* Add oauth required types

* create separate file

* delete misc

* OAuthApplication

* forgot to update import

* idk why that was here

src/util/constants.ts

@@ -164,4 +164,7 @@ export const endpoints = {
   USER_DM: `${baseEndpoints.BASE_URL}/users/@me/channels`,
   USER_CONNECTIONS: `${baseEndpoints.BASE_URL}/users/@me/connections`,
   USER_NICK: (guildID: string) => `${GUILDS_BASE(guildID)}/members/@me/nick`,
+
+  // oAuth2
+  OAUTH2_APPLICATION: `${baseEndpoints.BASE_URL}/oauth2/applications/@me`,
 };