Fix inconsistent quoting for some options in TAP tests

This commit addresses some inconsistencies with how the options of some
routines from PostgreSQL/Test/ are written, mainly for init() and
init_from_backup() in Cluster.pm.  These are written as unquoted, except
in the locations updated here.

Changes extracted from a larger patch by the same author.

Author: Dagfinn Ilmari Mannsåker <ilmari@ilmari.org>
Discussion: https://postgr.es/m/87jz8rzf3h.fsf@wibble.ilmari.org

src/test/perl/PostgreSQL/Test/Cluster.pm

@@ -1019,7 +1019,7 @@ sub init_from_backup
 		PostgreSQL::Test::RecursiveCopy::copypath(
 			$backup_path,
 			$data_path,
-			'filterfn' => sub {
+			filterfn => sub {
 				my ($path) = @_;
 				if ($path =~ /^pg_tblspc\/(\d+)$/
 					&& exists $params{tablespace_map}{$1})