This moves all magic-folder configs to a single YAML
file. We load legacy config fine and don't mess with
legacy config unless you use a magic-folder command that
changes the config.
Increase test coverage
* replace "last_details" with "non_connected_statuses" dict
* rename "last_connection_summary" to just "summary"
* for connected servers, show other hints in a tooltip
* for not-yet-connected servers, show all hints in a list
* build the list (in STAN) on the server side, not using IContainer
This shows current-connection info, and provides per-hint status details in a
tooltip.
The "Connection" section no longer shows seconds-since-loss when the server
was not connected (previously it showed seconds-since-connect when connected,
and flipped to seconds-since-loss when disconnected). We already have the
"Last RX" column, which is arguably more meaningful (and I can't think of a
good case when these would differ), so we don't really need
seconds-since-loss, and the new ConnectionStatus doesn't track it anyways.
So now the "Connection" timestamp for non-connected servers is just
"N/A" (both the main text and the tooltip). The "Introducers" section was
changed the same way.
This moves the per-server connection timestamp out of the nickname/serverid
box and over into the Connection box. It also right-floats all timestamps,
regardless of which box they're in, which makes them share the box with
connection_status more politely.
Internally, this adds code to create ConnectionStatus objects when necessary.
