[V3 RPC] Initial RPC library switch (#1634)

* Initial RPC library switch

* Use weak refs to the methods so cog unload works

* Add docs

* Black fixes

* Add jsonrpcserver to Pipfile.lock

redbot/core/bot.py

@@ -21,22 +21,9 @@ from .cog_manager import CogManager
 from . import Config, i18n, commands, rpc
 from .help_formatter import Help, help as help_
 from .sentry import SentryManager
-from .utils import TYPE_CHECKING
-
-if TYPE_CHECKING:
-    from aiohttp_json_rpc import JsonRpc
-
-# noinspection PyUnresolvedReferences
-class RpcMethodMixin:
-
-    async def rpc__cogs(self, request):
-        return list(self.cogs.keys())
-
-    async def rpc__extensions(self, request):
-        return list(self.extensions.keys())
 
 
-class RedBase(BotBase, RpcMethodMixin):
+class RedBase(BotBase):
     """Mixin for the main bot class.
 
     This exists because `Red` inherits from `discord.AutoShardedClient`, which
@@ -104,10 +91,11 @@ class RedBase(BotBase, RpcMethodMixin):
 
         self.cog_mgr = CogManager(paths=(str(self.main_dir / "cogs"),))
 
-        self.register_rpc_methods()
-
         super().__init__(formatter=Help(), **kwargs)
 
+        if self.rpc_enabled:
+            self.rpc = rpc.RPC(self)
+
         self.remove_command("help")
 
         self.add_command(help_)
@@ -275,10 +263,6 @@ class RedBase(BotBase, RpcMethodMixin):
             if pkg_name.startswith("redbot.cogs"):
                 del sys.modules["redbot.cogs"].__dict__[name]
 
-    def register_rpc_methods(self):
-        rpc.add_method("bot", self.rpc__cogs)
-        rpc.add_method("bot", self.rpc__extensions)
-
 
 class Red(RedBase, discord.AutoShardedClient):
     """