[libraries] - legacy categories move group by

[alikon]

Summary of Changes

group by is not necessary cause we have no function in the select

Testing Instructions

1. enable debug plugin
2. go to the home page
3. click on debug database tab
4. look fro this query #__categories
   
5. apply th pr
   you should see this one
   
   no more group by

Expected result

no group by

Actual result

unneeded group by

Documentation Changes Required