generalizes Deduper to work with any hashable type
Current Deduper is hard-coded only for Packet type. In order to use
Deduper in retransmit-stage, we need to dedup types other than Packet.
The commit generalizes Deduper to any hashable type.
removes the false_positive_rate field from the Deduper
Deduper.false_positive_rate field is misleading because it is not
enforced until maybe_reset is called. But then maybe_reset can be
invoked with an explicit argument.
Current Deduper implementation uses many bits per entry:
https://github.com/solana-labs/solana/blob/65cd55261/perf/src/deduper.rs#L70-L73
and may be saturated quickly. It also lacks api to specify desired false
positive rate.
The commit instead uses an atomic bloom filter with K hash functions.
The false positive rate is obtained by tracking popcount of bits.
Upcoming changes to PacketBatch to support variable sized packets will
modify the internals of PacketBatch. So, this change removes usage of
the internal packet struct and instead uses accessors (which are
currently just wrappers of Vector functions but will change down the
road).