Move casting to IExpressionBuilder

apps/files/lib/backgroundjob/deleteorphaneditems.php

...e/db/querybuilder/expressionbuilder/expressionbuilder.php

...b/querybuilder/expressionbuilder/ociexpressionbuilder.php

...querybuilder/expressionbuilder/pgsqlexpressionbuilder.php

lib/private/db/querybuilder/querybuilder.php

lib/public/db/querybuilder/iexpressionbuilder.php

tests/lib/db/querybuilder/expressionbuildertest.php

tests/lib/share/share.php