fixes #6812 : Zend\Paginator\Adapter\DbSelect::getItems should return array
change Zend\Paginator\Paginator::getItemsByPage() as suggested by @Martin-P
added unit test for #6817
update DbSelect adapter instead for return array() as interface contract
update back to @return array
fixes cs : braces
change loop resultSet with Zend\Stdlib\ArrayUtils::iteratorToArray
patch trailing_spaces and add @group for PR
change ArrayUtils::iteratorToArray() to iterator_to_array() instead
assert ArrayIterator and ArrayObject
#6812 #6817 - minor CS fixes (spacing)
#6812 #6817 - `$dataSource` can be an `array`
#6812 #6817 - constant use over magic constant: see #5505 for reference
#6812 #6817 - CS: whitespace removal
#6812 #6817 - `DbSelect#getItems()` should return `array` types
#6812 #6817 - fixed `@group` annotations to comply with `DbSelectTest` ones
Merge branch 'hotfix/#6817-zend-paginator-dbselect-getitems-should-return-array' into develop

Close #6812
Close #6817