For the upcoming port of network-grpc to tower-hyper, it's convenient to add a requirement for future and stream objects returned by the network-core service implementation API to be sendable between threads.
Required for #717.
Other changes in this PR:
Updated tower-grpc to the latest revision that supported tower-h2.
Removed the obsolete method propose_transactions from ContentService and stubbed out its use
in network-ntt.
For the upcoming port of network-grpc to tower-hyper, it's convenient to add a requirement for future and stream objects returned by the network-core service implementation API to be sendable between threads.
Required for #717.
Other changes in this PR:
propose_transactionsfromContentServiceand stubbed out its use in network-ntt.