Improve support for special characters in filenames.

% characters caused issues in backup/restore due to filenames being appended directly into a format string.

Reserved XML characters (<>&') caused issues in the S3 driver due to improper escaping.

Add a file with all common special characters to regression testing.

test/lib/pgBackRestTest/Module/Mock/MockAllTest.pm

@@ -362,6 +362,10 @@ sub run
                                               'e350d5ce0153f3e22d5db21cf2a4eff00f3ee877', $lTime - 100, undef, true);
         $oHostDbMaster->manifestPathCreate(\%oManifest, MANIFEST_TARGET_PGDATA, 'pg_clog');
 
+        # Create file with special characters
+        $oHostDbMaster->manifestFileCreate(
+            \%oManifest, MANIFEST_TARGET_PGDATA, 'special-@!#$^&*()-_+~`{}[]\|:;"<>\',.?%', undef, undef, $lTime, undef, true);
+
         $strFullBackup = $oHostBackup->backup(
             $strType, 'create pg_stat link, pg_clog dir',
             {oExpectedManifest => \%oManifest,