feat: add Medusa Cloud OAuth provider (#14395)

* feat: add Medusa Cloud OAuth provider

* add Cloud login button

* fetch whether cloud auth is enabled through api

* allow unregistered to get session

* handle existing users

* address PR comments

* prevent double execution

* a few more fixes

* fix callback url

* fix spelling

* refresh session

* 200 instead of 201

* only allow cloud identities to create user

* fix condition

.changeset/humble-sides-matter.md

@@ -0,0 +1,7 @@
+---
+"@medusajs/auth": patch
+"@medusajs/types": patch
+"@medusajs/utils": patch
+---
+
+add Medusa Cloud auth provider