Rewrite pg_dump TAP tests

This reworks how the tests to run are defined.  Instead of having to
define all runs for all tests, we define those tests which should pass
(generally using one of the defined broad hashes), add in any which
should be specific for this test, and exclude any specific runs that
shouldn't pass for this test.  This ends up removing some 4k+ lines
(more than half the file) but, more importantly, greatly simplifies the
way runs-to-be-tested are defined.

As discussed in the updated comments, for example, take the test which
does CREATE TABLE test_table.  That CREATE TABLE should show up in all
'full' runs of pg_dump, except those cases where 'test_table' is
excluded, of course, and that's exactly how the test gets defined now
(modulo a few other related cases, like where we dump only that table,
or we dump the schema it's in, or we exclude the schema it's in):

like => {
    %full_runs,
    %dump_test_schema_runs,
    only_dump_test_table    => 1,
    section_pre_data        => 1, },
unlike => {
    exclude_dump_test_schema => 1,
    exclude_test_table => 1, }, },

Next, we no longer expect every run to be listed for every test.  If a
run is listed in 'like' (directly or through a hash) then it's a 'like',
unless it's listed in 'unlike' in which case it's an 'unlike'.  If it
isn't listed in either, then it's considered an 'unlike' automatically.

Lastly, this changes the code to no longer use like/unlike but rather to
use 'ok()' with 'diag()' which allows much more control over what gets
spit out to the screen.  Gone are the days of the entire dump being sent
to the console, now you'll just get a couple of lines for each failing
test which say the test that failed and the run that it failed on.

This covers both the pg_dump TAP tests in src/bin/pg_dump and those in
src/test/modules/test_pg_dump.