[Core] Guild scoped I18n (#3896)

* Guild I18n

Never again!

* Finish off guild scoped i18n

* Black formatting

* Added guild only flags.

* Fix missing import.

* Added listing of guild i18n settings

* Added API support

* Added API support... properly!

* Added API support... for realsies!

* Auto-translate create_cases instances

You're welcome cog creators! Jack talked me into this!

* Fix get_regional_format to actually return properly

* Cleanup `set showsettings`

* Style pass

* Update redbot/core/core_commands.py

Co-authored-by: jack1142 <6032823+jack1142@users.noreply.github.com>

* Update redbot/core/events.py

Co-authored-by: jack1142 <6032823+jack1142@users.noreply.github.com>

* Update redbot/core/core_commands.py

Co-authored-by: jack1142 <6032823+jack1142@users.noreply.github.com>

* Fix missing import

* Improve caching

* Removal of unneeded function

* Fix some naming

* IDFK anymore...

* Reformat

* Update redbot/core/settings_caches.py

Co-authored-by: jack1142 <6032823+jack1142@users.noreply.github.com>

* Update redbot/core/settings_caches.py

Co-authored-by: jack1142 <6032823+jack1142@users.noreply.github.com>

* Update redbot/core/settings_caches.py

Co-authored-by: jack1142 <6032823+jack1142@users.noreply.github.com>

* Remove line number

* Fix global sets

* Set contextual locale manually where needed

* Reports cog is wonderful...

* Update redbot/core/core_commands.py

Co-authored-by: Draper <27962761+Drapersniper@users.noreply.github.com>

* Set contextual locale manually where needed in Mutes cog

* s

Co-authored-by: jack1142 <6032823+jack1142@users.noreply.github.com>
Co-authored-by: Draper <27962761+Drapersniper@users.noreply.github.com>

redbot/cogs/alias/alias.py

@@ -170,7 +170,7 @@ class Alias(commands.Cog):
         for p in prefixes:
             if content.startswith(p):
                 return p
-        raise ValueError(_("No prefix found."))
+        raise ValueError("No prefix found.")
 
     async def call_alias(self, message: discord.Message, prefix: str, alias: AliasEntry):
         new_message = copy(message)