Fixes#7667.
Implements the plan described in #7667.
Here's a terminal log showing that it does so:
```
# sudo snap connect certbot:plugin certbot-dns-dnsimple
error: cannot perform the following tasks:
- Run hook prepare-plug-plugin of snap "certbot" (run hook "prepare-plug-plugin":
-----
Only connect this interface if you trust the plugin author to have root on the system
Run `snap set certbot trust-plugin-with-root=ok` to acknowledge this and then run this command again to perform the connection
-----)
# snap set certbot trust-plugin-with-root=ok
# sudo snap connect certbot:plugin certbot-dns-dnsimple
# sudo snap disconnect certbot:plugin certbot-dns-dnsimple:certbot
# sudo snap connect certbot:plugin certbot-dns-dnsimple
error: cannot perform the following tasks:
- Run hook prepare-plug-plugin of snap "certbot" (run hook "prepare-plug-plugin":
-----
Only connect this interface if you trust the plugin author to have root on the system
Run `snap set certbot trust-plugin-with-root=ok` to acknowledge this and then run this command again to perform the connection
-----)
```
* Add plugin connection hook to accept root trust
* snapctl requires a configure hook to set options
* Add sh notice
* Update changelog
