Add public positive_int and finite_float converters (#5969)

Co-authored-by: Kreusada <67752638+Kreusada@users.noreply.github.com>

redbot/cogs/cleanup/converters.py

@@ -1,8 +1,5 @@
-from typing import NewType, TYPE_CHECKING
-
 from redbot.core.commands import BadArgument, Context, Converter
 from redbot.core.i18n import Translator
-from redbot.core.utils.chat_formatting import inline
 
 _ = Translator("Cleanup", __file__)
 
@@ -15,18 +12,3 @@ class RawMessageIds(Converter):
             return int(argument)
 
         raise BadArgument(_("{} doesn't look like a valid message ID.").format(argument))
-
-
-PositiveInt = NewType("PositiveInt", int)
-if TYPE_CHECKING:
-    positive_int = PositiveInt
-else:
-
-    def positive_int(arg: str) -> int:
-        try:
-            ret = int(arg)
-        except ValueError:
-            raise BadArgument(_("{arg} is not an integer.").format(arg=inline(arg)))
-        if ret <= 0:
-            raise BadArgument(_("{arg} is not a positive integer.").format(arg=inline(arg)))
-        return ret