Add a "On/Off" button for each plugin

[bxlouis]

Is your feature request related to a problem? Please describe:
I recently had an issue with my Raspberry Pi, resulting in some services being down for a couple of days.
During this time, I would have liked to be able to simply disable the Homberidge plugins that were linked to these services.

Describe the solution you'd like:
On the plugin page, add an "On/Off" button to each listed plugin.
Turning a plugin "Off" would comment it in the JSON config file, allowing to pause it without loosing the configuration.
Turning a plugin "On" would uncomment the JSON config file.

Describe alternatives you've considered:
Manually comment the config file.

[masterfordev]

It is a very good idea, hopefully it can be implemented.

[oznu]

Would be the same implementation as #287 - closing this in favour of that one.