Add a custom Logger class with both verbose and trace levels. (#5613)

* rearrange commits

* Update redbot/setup.py

* change rich log level colours

redbot/_log.py

@@ -0,0 +1,22 @@
+import logging as _logging
+
+__ALL__ = ["VERBOSE", "TRACE", "RedTraceLogger"]
+
+VERBOSE = _logging.DEBUG - 3
+TRACE = _logging.DEBUG - 5
+
+
+class RedTraceLogger(_logging.getLoggerClass()):
+    def __init__(self, name, level=_logging.NOTSET):
+        super().__init__(name, level)
+
+        _logging.addLevelName(VERBOSE, "VERBOSE")
+        _logging.addLevelName(TRACE, "TRACE")
+
+    def verbose(self, msg, *args, **kwargs):
+        if self.isEnabledFor(VERBOSE):
+            self._log(VERBOSE, msg, args, **kwargs)
+
+    def trace(self, msg, *args, **kwargs):
+        if self.isEnabledFor(TRACE):
+            self._log(TRACE, msg, args, **kwargs)