bpo-28307: Convert simple C-style formatting with literal format into f-string. ...

bpo-28307: Convert simple C-style formatting with literal format into f-string. (GH-5012)

C-style formatting with literal format containing only format codes
%s, %r and %a (with optional width, precision and alignment)
will be converted to an equivalent f-string expression.

It can speed up formatting more than 2 times by eliminating
runtime parsing of the format string and creating temporary tuple.