Bump discord.py to 1.7.0 (#4928)

* Bump discord.py, but to the git version for now

* Import GuildConverter from d.py and deprecate our implementation

* Import PartialMessageConverter in our commands extension

* Use newly added `Cog.has_error_handler()` rather than private method

* Update snowflake regex to use 20 as max length

See Rapptz/discord.py#6501

* Use new supported way for custom cooldown buckets

* Include group args in command signature

* Update code to use `Client.close()` over `Client.logout()`

* Add StageChannelConverter and StoreChannelConverter

* Fix AttributeError in licenseinfo

redbot/core/commands/converter.py

@@ -35,7 +35,6 @@ if TYPE_CHECKING:
 
 __all__ = [
     "DictConverter",
-    "GuildConverter",
     "UserInputOptional",
     "NoParseOptional",
     "TimedeltaConverter",
@@ -47,7 +46,7 @@ __all__ = [
 
 _ = Translator("commands.converter", __file__)
 
-ID_REGEX = re.compile(r"([0-9]{15,21})")
+ID_REGEX = re.compile(r"([0-9]{15,20})")
 
 
 # Taken with permission from
@@ -134,29 +133,46 @@ def parse_timedelta(
     return None
 
 
-class GuildConverter(discord.Guild):
+class _GuildConverter(discord.Guild):
     """Converts to a `discord.Guild` object.
 
     The lookup strategy is as follows (in order):
 
     1. Lookup by ID.
     2. Lookup by name.
+
+    .. deprecated-removed:: 3.4.8 60
+        ``GuildConverter`` is now only provided within ``redbot.core.commands`` namespace.
     """
 
     @classmethod
     async def convert(cls, ctx: "Context", argument: str) -> discord.Guild:
-        match = ID_REGEX.fullmatch(argument)
+        return await dpy_commands.GuildConverter().convert(ctx, argument)
 
-        if match is None:
-            ret = discord.utils.get(ctx.bot.guilds, name=argument)
-        else:
-            guild_id = int(match.group(1))
-            ret = ctx.bot.get_guild(guild_id)
 
-        if ret is None:
-            raise BadArgument(_('Server "{name}" not found.').format(name=argument))
+_GuildConverter.__name__ = "GuildConverter"
 
-        return ret
+
+def __getattr__(name: str, *, stacklevel: int = 2) -> Any:
+    # Let me just say it one more time... This is awesome! (PEP-562)
+    if name == "GuildConverter":
+        # let's not waste time on importing this when we don't need it
+        # (and let's not put in the public API)
+        from redbot.core.utils._internal_utils import deprecated_removed
+
+        deprecated_removed(
+            "`GuildConverter` from `redbot.core.commands.converter` namespace",
+            "3.4.8",
+            60,
+            "Use `GuildConverter` from `redbot.core.commands` namespace instead.",
+            stacklevel=2,
+        )
+        return globals()["_GuildConverter"]
+    raise AttributeError(f"module {__name__!r} has no attribute {name!r}")
+
+
+def __dir__() -> List[str]:
+    return [*globals().keys(), "GuildConverter"]
 
 
 # Below this line are a lot of lies for mypy about things that *end up* correct when