TX pause solution

[sea212]

Sometimes it is necessary to block operation of some modules or most parts of the protocol, for example when a hack occurred or a bug was found that causes immense damage. In such scenarios, it would be good to dynamically configure the BaseCallFilter to enable or disable certain calls. The technical committee could get the privilege to apply those call filters, the approval ratio should be quite high though (75-100%) since this is such a powerful operation.

Substrates tx-pause pallet, Substrates safe-mode pallet or Moonbeams maintenance pallet can be used for inspiration.