Begin work on a data request API (#4045)

[Core] Data Deletion And Disclosure APIs

 - Adds a Data Deletion API
   - Deletion comes in a few forms based on who is requesting
   - Deletion must be handled by 3rd party
 - Adds a Data Collection Disclosure Command
   - Provides a dynamically generated statement from 3rd party
   extensions
 - Modifies the always available commands to be cog compatible
   - Also prevents them from being unloaded accidentally

redbot/cogs/image/image.py

@@ -26,6 +26,10 @@ class Image(commands.Cog):
     def cog_unload(self):
         self.session.detach()
 
+    async def red_delete_data_for_user(self, **kwargs):
+        """ Nothing to delete """
+        return
+
     async def initialize(self) -> None:
         """Move the API keys from cog stored config to core bot config if they exist."""
         imgur_token = await self.config.imgur_client_id()