While debugging a hanging change I noticed that we lack some tests
related to the undo handling of bad services. This PR adds two
new tests:
1. A snap where the new snap service is broken and the refresh breaks
the old snap service as well
2. A snap where the stop command takes forever
cmd/snap, client, daemon, ifacestate: show a leading attribute of a connection (#6576)
* dameon: include connection plug/slot attributes in /v2/connections endpoint
* overlord/ifacestate: extend connections state API to include plug/slot attributes
* client: add definitions for connection plug/slot attributes
* cmd/snap: show leading attribute when displaying connections
Some interfaces, such as 'content', have an attribute that is used internally to
match the plug and slot. Display the value of the leading attribute of an
established connection in 'snap connections' output.
* tests/main/snap-connections: account for content interface attributes