Moves to a nicely spaced GtkListBox. The avatar is implemented using AdwAvatar solely for the autogenerated colour for accounts without an icon to give them some uniqueness, but it could be moved to PidginAvatar.
As a followup, I'd probably move the Account Editors from a separate dialog to stack within the manager, similar to how the Plugin dialog works. Neither the previous manager nor this one prevents you from opening two editors for an account, but this would remove that issue as well.

Toggled enabled/disabled to check that account status worked and was displayed. Added a few bogus accounts to confirm that errors are shown. Activated a row to show the editor. Hit the delete button and cancelled/approved and confirmed that account was kept/removed.