Use kvdb package v1.4.1. This update also forced the protobuf version to
be bumped which required `make rpc` to be run to update the generated
files. This also required a bump in the github pinned dependencies
config for the grpc and protobuf libs.
As a preparation for the migration to the grpc-gateway/v2 library we
declare each service's REST annotations in its own file. This is
optional in the v1 library but mandatory in v2.
