Type convertion for f-string

[dg-pb]

Having that said, I am not opposed if someone wants to make effort.

E.g. I added n/N/t/T to string.Formatter for myself:

!n = obj.__qualname__
!N = obj.__module__:obj.__qualname__
!t = type(obj).__qualname__
!T = type(obj).__module__:type(obj).__qualname__