[repo] move repo.gc_stats to Service API (closes #2951068) We currently have a method on the repo that anyone can call. `call_service` gives a similar thing, modulo: * can be restricted access to manager only (thanks to selection on services), * less unrelated code on the repository class, * no need to fetch a reference to a repo object from the client side * (`req._cnx.repo` is not an API and config.repository() is on its way out). The old way to access this information (repo.gc_stats()) is deprecated.

/***************************************/
/* Manage view (views/startup.py)      */
/***************************************/

table.startup {
  width: 100%;
}

/* table.startup td { */
/*   padding: 0.1em 0.2em; */
/* } */

table.startup td.addcol {
  text-align: right;
  width: 0.5em;
}

table.startup th{
  text-align: left;
}