List the SqlInstance available settings.

[MoElkhidir]

Reasoning
As part of our build pipeline, we would like to warn users about expected SqlInstance restart if specific settings or database flags values have been changed.

Expected solution
I would like to be able to list the available settings for SqlInstance with their description similar to the currently available listing of Database Flags.

Describe alternatives you've considered
Currently, we statically store these settings in our app's configuration.

Additional context
current available database flags can be fetched using SqlAdmin.flags().list(), something similar like SqlAdmin.instance.settings.list to list SqlInstance settings would be very much appreciated