Added the limit, offset support to DB2
Fixed some php-cs issues
Fixed and simplified the ROW_NUMBER() usage for DB2
Remove the FIRST FETCH ROW ONLY and refactored the DB2 pagination
Added the transactions support for DB2
Merge pull request #6446 from ezimuel/fix/#6445

Fix for #6445, adding pagination and transaction to IBM DB2 for Zend\Db
[#6446] CS + Review

- Formatted several conditionals to 1 per line
- Formatted several arrays to 1 per line
- Removed unnecessary whitespace
- Slight logic modifications for readability, consistency
- Ensured docblocks are correct
Merge branch 'hotfix/6446'

Close #6446
Fixes #6445