Sort entries in the admin UI and apply proper pagination #1420

Is your feature request related to a problem? Please describe.
Entries in the dashboard and users tabs of the admin UI are not sorted (the repositories tab does have a sorting control, but it doesn't seem to affect the sort order currently). The lack of sorting makes the dashboard, in particular, difficult to use once you have accumulated a number of entries.

(server-side) Pagination should also be applied, we currently retrieve all entries and paginate client-side, which is not sustainable.

Describe the solution you'd like
The repository, dashboard and user views should all sort the selection of a sort order and page size. These (and the current page number) should be applied to data queries. Additionally, the currently selected status of pushes (all / pending / rejected / cancelled / error) should be applied as a filter to push queries (or we can't figure out the right page size until we receive the data).

• The dashboard should default to sorting by timestamp (most recent first).
• The repository tab should default to alphabetical sorting on project name.
• The users tab should default to alphabetical sorting on username.

Describe alternatives you've considered
Continuing without sorting or server-side pagination is not sustainable. Hence, the alternative is to defer fixing the admin UI is replaced in full.

Additional context
The DB clients and API service already support passing parameters to queries (with the exception of the limit and skip parameters in the API service for some reason). That facility should be used to apply server-side pagination and sorting.