test_pg_dump: perltidy cleanup

As pointed out by Alvaro, we actually use perltidy on the perl scripts
in the source tree, so go back to the results of a perltidy run for the
test_pg_dump TAP script.

To make it look slightly less tragic, I changed most of the independent
arguments into long-form single arguments (eg: -f file.sql changed to be
--file=file.sql) to avoid having them confusingly split across lines due
to perltidy.

Back-patch to 9.6, as the last patch was.