_bleio: Pass connection to PacketBuffer, its Characteristic, or its Service

[dhalbert]

PacketBuffer needs to know about its Connection to determine .incoming_packet_length and .outgoing_packet_length. When its Characteristic is remote, the Connection is know via the Service, but when the Characteristic and Service are local, the Connection is not easily found. Right now, PacketBuffer grabs the conn_handle by spying on GATTS write operations, and also notices disconnections.

It might make more sense for the Python program simply to pass the Connection in, once a connection has been established. This could be to the PacketBuffer itself, or to the Service. An API like Service.connection = or similar could be used.

This would be an incompatible change, deferred until 6.0.0.

[tannewt]

@dhalbert Still want to do this in 6.0.0 or punt to 7.0.0?

[dhalbert]

Ok to move to 7.0.0. I'll change the milestone.