implement bitfield distribution subsystem (#1368)

* feat bitfield distribution

* feat bitfield distribution part 2

* pair programming with rustc & cargo

* lets go

* move bitfield-distribution to the node/network folder

* shape shifting

* lunchtime

* ignore the two fn recursion for now

* step by step

* triplesteps

* bandaid commit

* unordered futures magic

* chore

* reword markdown

* clarify

* lacks abortable processing impl details

* slimify

* fix: warnings and avoid ctx.clone() improve comments

* review comments

* fix details

* make sure outgoing messages are tracked

* fix name

* fix subsystem

* partial test impl

* relax context bounds

* test

* X

* X

* initial test

* fix relay_message not tracked when origin is self

* fix/guide: grammar

Co-authored-by: Robert Habermeier <[email protected]>

* work around missing Eq+PartialEq

* fix: add missing message to provisioner

* unify per_job to job_data

* fix/review: part one

* fix/review: more grumbles

* fix/review: track incoming messages per peer

* fix/review: extract fn, avoid nested matches

* fix/review: more tests, simplify test

* fix/review: extend tests to cover more cases

* chore/rename: Tracker -> ProtocolState

* chore check and comment rewording

* feat test: invalid peer message

* remove ignored test cases and unused macros

* fix master merge fallout + warnings

Co-authored-by: Robert Habermeier <[email protected]>