Support removing deprecated machines in Sentinel dashboard

[naturalyui]

Issue Description

When I debug locally, I change the list of the console of the port console to one more line of data. At present, I can only clean up the list of machines by restarting the console, but since I have not been able to persist the rules to naocs, so every time I do It takes a lot of difficulty to re-specify the rules.

[sczyh30]

Hi, it's necessary to provide functions for removing unused machines. We'll add interfaces and entries to it. Something to be considered:

• Support manually remove the machine in the machine list page
• Maybe it's necessary to support automatic removal after a machine has been marked as disconnected state for some time (this should be configurable)
• When an application has no connected machines in machine list, this application might not be displayed in the app list (sidebar). This should also be configurable.

For a temporary solution, you can refer to this PR: #168

[naturalyui]

ok