Update use statement lists with new Friendica\Database\dba class

- Remove unused use statement
- Remove superfluous use statements (classes in the same namespace)
- Add missing use statements

src/Core/Worker.php

@@ -4,7 +4,7 @@
  */
 namespace Friendica\Core;
 
-use dba;
+use Friendica\Database\dba;
 use Friendica\Database\DBM;
 use Friendica\Model\Process;
 use Friendica\Util\DateTimeFormat;