Peter M. Groen / oletools

If there is an error in log-handling (e.g. wrong args to logger call) do
not fail or raise but produce something helpful

Need to make sure that json output is formatted since e.g. warning messages
are created like this:
   log.warning('%s', actual_message)
so without proper formatting the message is just "%s".

Also test that exception info is added as usual.

Encountered an example where a 3rd-party library issued a warning that
messed up the json output. Create test to reproduce this.

Every logging call can have an optional arg type='...' which is
ignored when logging to text but shows in json output. The "type"
of regular logging output in json is type='msg'.

Added 2 messages with different type, adjusted existing test, created
2 new ones.