Bit signaling ,ok to internet'

[dl9sau]

Again and again we have discussions about privacy.

MT has a bit in the header for ,ok to mqtt'. So user has an option to decide if his nodeinfo/position/text is granted to be gated to foregn networks like the internet.

Unfortunately, MC did not had this in mind when designing the protocol.

I think this feature is necessary for being compliant to gpdr.

[liamcottle]

Please see #435 for previous discussions on this.