[Config] Migrate UUID for JSON backend (#2604)

* Migrate UUID for JSON backend

* Interesting...

* black

* Simplify UUID creation

redbot/core/config.py

@@ -7,7 +7,7 @@ import weakref
 import discord
 
 from .data_manager import cog_data_path, core_data_path
-from .drivers import get_driver, IdentifierData
+from .drivers import get_driver, IdentifierData, BackendType
 
 if TYPE_CHECKING:
     from .drivers.red_base import BaseDriver
@@ -562,6 +562,10 @@ class Config:
     def defaults(self):
         return deepcopy(self._defaults)
 
+    @staticmethod
+    def _create_uuid(identifier: int):
+        return str(identifier)
+
     @classmethod
     def get_conf(cls, cog_instance, identifier: int, force_registration=False, cog_name=None):
         """Get a Config instance for your cog.
@@ -602,7 +606,8 @@ class Config:
             cog_path_override = cog_data_path(cog_instance=cog_instance)
 
         cog_name = cog_path_override.stem
-        uuid = str(hash(identifier))
+        # uuid = str(hash(identifier))
+        uuid = cls._create_uuid(identifier)
 
         # We have to import this here otherwise we have a circular dependency
         from .data_manager import basic_config
@@ -613,6 +618,9 @@ class Config:
         driver = get_driver(
             driver_name, cog_name, uuid, data_path_override=cog_path_override, **driver_details
         )
+        if driver_name == BackendType.JSON.value:
+            driver.migrate_identifier(identifier)
+
         conf = cls(
             cog_name=cog_name,
             unique_identifier=uuid,