Fix tests

- Fix InstallerTest case
- Fix native function mocking
- Add returntype for Unit-Tests
- Fixing ExtendedPDO test troubles
- Fix wrong class inheritance path for DatabaseTestTrait.php
- Fix SyslogLogger Server Exception for PHP8
- Add user/contact to database.fixture.php
- Avoid invalid rollbacks for test setup in PHP8

tests/src/Core/Lock/SemaphoreLockTest.php

@@ -32,7 +32,7 @@ use Mockery\MockInterface;
 
 class SemaphoreLockTest extends LockTest
 {
-	protected function setUp()
+	protected function setUp(): void
 	{
 		/** @var MockInterface|Dice $dice */
 		$dice = Mockery::mock(Dice::class)->makePartial();