refactors FPC

go.mod

go.sum

packages/prng/unix_ts_rng.go

packages/prng/unix_ts_rng_test.go

packages/shutdown/order.go

packages/vote/fpc/fpc.go

packages/vote/fpc/fpc_test.go

packages/vote/fpc/parameters.go

packages/vote/fpc/vote_context.go

packages/vote/net/query.pb.go

packages/vote/net/query.proto

packages/vote/net/server.go

packages/vote/opinion.go

packages/vote/voter.go

plugins/fpc/parameters.go

plugins/fpc/plugin.go