adds giant refresh all button at top of the available (aka catalog) view which fetches updates to all the catalogs
given the way the catalog stuff works internally these changes fall short of delivering the desired user experience. specifically:
the completion dialog for the refresh all catalog action only lists the catalogs which were updated but it doesn't give any indication if there were new entries or not
catalogs which fail to update will be reported as having been updated if the catalog was downloaded previously. update failures are only shown if the catalog does not exist on the device
available(aka catalog) view which fetches updates to all the catalogsgiven the way the catalog stuff works internally these changes fall short of delivering the desired user experience. specifically:
fixes: #184