Make checks in Bank, Economy and Trivia cogs Permissions-friendly (#3672)

* Create converters.py

* Update trivia.py

* Create checks.py

* Update checks.py

* Update checks.py

* Update trivia.py

* Update checks.py

* Update checks.py

* Update trivia.py

* Update bank.py

* Update economy.py

* Update trivia.py

* Update checks.py

* Update checks.py

* Update __init__.py

redbot/cogs/trivia/converters.py

@@ -0,0 +1,18 @@
+import math
+
+from redbot.core import commands
+from redbot.core.i18n import Translator
+
+__all__ = ("finite_float",)
+
+_ = Translator("Trivia", __file__)
+
+
+def finite_float(arg: str) -> float:
+    try:
+        ret = float(arg)
+    except ValueError:
+        raise commands.BadArgument(_("`{arg}` is not a number.").format(arg=arg))
+    if not math.isfinite(ret):
+        raise commands.BadArgument(_("`{arg}` is not a finite number.").format(arg=ret))
+    return ret