[HACKERS] PGSERVICEFILE as a connection string parameter

Hi all,

I bumped into a case where it would have been rather useful to specify
a service file path in a connection string with a service name. In my
case, I have finished by setting up PGSERVICEFILE, but now like
PGPASSFILE I think that being able to define the service file
available as well as a connection parameter would be useful as well.

I am not planning to work on that immediately (there is one day left
for the last CF of PG10!), but I was wondering if people would be
interested in something like that.
So, opinions?
-- 
Michael