pgsql compat preparation

[staabm]

pgsql expects single-quotes in queries.

to make tests cross-db compatible, we use single quotes also for mysql

1) Error
The data provider specified for staabm\PHPStanDba\Tests\DbaInferenceTest::testFileAsserts is invalid.
PDOException: SQLSTATE[42601]: Syntax error: 7 ERROR:  zero-length delimited identifier at or near """"
LINE 2:                     coalesce(COLUMN_NAME, "") as COLUMN_NAME...
                                                  ^
/home/runner/work/phpstan-dba/phpstan-dba/src/QueryReflection/PdoQueryReflector.php:104
/home/runner/work/phpstan-dba/phpstan-dba/src/QueryReflection/BasePdoQueryReflector.php:146
/home/runner/work/phpstan-dba/phpstan-dba/src/QueryReflection/PdoQueryReflector.php:74
/home/runner/work/phpstan-dba/phpstan-dba/src/QueryReflection/BasePdoQueryReflector.php:96
/home/runner/work/phpstan-dba/phpstan-dba/src/QueryReflection/RecordingQueryReflector.php:47
/home/runner/work/phpstan-dba/phpstan-dba/src/QueryReflection/QueryReflection.php:68
/home/runner/work/phpstan-dba/phpstan-dba/src/DoctrineReflection/DoctrineReflection.php:173
/home/runner/work/phpstan-dba/phpstan-dba/src/Extensions/DoctrineConnectionQueryDynamicReturnTypeExtension.php:71
/home/runner/work/phpstan-dba/phpstan-dba/src/Extensions/DoctrineConnectionQueryDynamicReturnTypeExtension.php:56
phar:///home/runner/work/phpstan-dba/phpstan-dba/vendor/phpstan/phpstan/phpstan.phar/src/Analyser/MutatingScope.php:3951
phar:///home/runner/work/phpstan-dba/phpstan-dba/vendor/phpstan/phpstan/phpstan.phar/src/Analyser/MutatingScope.php:1691
phar:///home/runner/work/phpstan-dba/phpstan-dba/vendor/phpstan/phpstan/phpstan.phar/src/Analyser/MutatingScope.php:1697
phar:///home/runner/work/phpstan-dba/phpstan-dba/vendor/phpstan/phpstan/phpstan.phar/src/Analyser/MutatingScope.php:551
phar:///home/runner/work/phpstan-dba/phpstan-dba/vendor/phpstan/phpstan/phpstan.phar/src/Analyser/NodeScopeResolver.php:1424
phar:///home/runner/work/phpstan-dba/phpstan-dba/vendor/phpstan/phpstan/phpstan.phar/src/Analyser/NodeScopeResolver.php:2593
phar:///home/runner/work/phpstan-dba/phpstan-dba/vendor/phpstan/phpstan/phpstan.phar/src/Analyser/NodeScopeResolver.php:1434
phar:///home/runner/work/phpstan-dba/phpstan-dba/vendor/phpstan/phpstan/phpstan.phar/src/Analyser/NodeScopeResolver.php:515
phar:///home/runner/work/phpstan-dba/phpstan-dba/vendor/phpstan/phpstan/phpstan.phar/src/Analyser/NodeScopeResolver.php:316
phar:///home/runner/work/phpstan-dba/phpstan-dba/vendor/phpstan/phpstan/phpstan.phar/src/Analyser/NodeScopeResolver.php:478
phar:///home/runner/work/phpstan-dba/phpstan-dba/vendor/phpstan/phpstan/phpstan.phar/src/Analyser/NodeScopeResolver.php:316
phar:///home/runner/work/phpstan-dba/phpstan-dba/vendor/phpstan/phpstan/phpstan.phar/src/Analyser/NodeScopeResolver.php:562
phar:///home/runner/work/phpstan-dba/phpstan-dba/vendor/phpstan/phpstan/phpstan.phar/src/Analyser/NodeScopeResolver.php:316
phar:///home/runner/work/phpstan-dba/phpstan-dba/vendor/phpstan/phpstan/phpstan.phar/src/Analyser/NodeScopeResolver.php:528
phar:///home/runner/work/phpstan-dba/phpstan-dba/vendor/phpstan/phpstan/phpstan.phar/src/Analyser/NodeScopeResolver.php:287
phar:///home/runner/work/phpstan-dba/phpstan-dba/vendor/phpstan/phpstan/phpstan.phar/src/Testing/TypeInferenceTestCase.php:43
phar:///home/runner/work/phpstan-dba/phpstan-dba/vendor/phpstan/phpstan/phpstan.phar/src/Testing/TypeInferenceTestCase.php:121
/home/runner/work/phpstan-dba/phpstan-dba/tests/default/DbaInferenceTest.php:13

see https://stackoverflow.com/questions/23165282/error-zero-length-delimited-identifier-at-or-near-line-1-delete-from-reg

backported from #328