Dependencies list grouping: Change from gitlab-ui table to list of expandable items

We currently use a gitlab-ui table to display the list of dependencies for a group.

To add the group-by option, we need to change this to use a list of expandable/collapsible items, with each containing a table that displays the dependencies for the current item:

Note: Each group-by option will show slightly different information on the top-level item, so we need to account for that and possible use slots, etc. to make it flexible enough.