Add ids argument for descendant groups

What does this MR do and why?

This merge request adds a new feature to filter groups by their IDs in a GraphQL query. The changes include:

1. Adding a new argument called 'ids' to the NestedGroupsResolver class, which allows users to provide a list of group IDs to filter the results.
2. Updating the API documentation to include information about the new 'ids' filter option.
3. Adding a new test case to verify that the 'ids' filter works correctly when querying for specific groups.

These changes enhance the flexibility of group queries by allowing users to retrieve specific groups by their IDs, in addition to the existing search and ownership filters.

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Description	UI
Ids argument for descendant groups

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

1. Go to graphql-explorer

2. Test the query:

   {
     group(fullPath: "path-to-agroup") {
       descendantGroups(ids: [list of gids]) {
         nodes {
           name
           id
         }
       }
     }
   }

Related to #520943 (closed)