Instead of using Vec<u8> to represent raw content keys/values, we should use something like alloy_primitives::Bytes because:

• copy is faster
• (de)serializes into hex string correctly

We should either wrap or name the type, to avoid potential confusion (e.g. see RawContentValue).

Other places that should be updated:

• ethportal-api/src/types/portal_wire.rs
  • FindContent::content_key - type should be RawContentKey
  • Content::Content(Vec<u8>) -> Content::Content(RawContentValue)
  • PopulatedOffer::content items - type should be Vec<(RawContentKey, RawContentValue)>
    • same with PopulatedOfferWithResult
• portalnet/src/find/query_info.rs
  • RecursiveFindContentResult - should be RawContentValue instead of Vec<u8>
• portalnet/src/find/iterators/findcontent.rs
  • FindContentQueryResponse::Content - should be RawContentValue
  • FindContentQueryPending::PendingContent.content - should be RawContentValue
  • UnvalidatedContent::Content - should be RawContentValue
  • ValidatedContent.content - should be RawContentValue
• portalnet/src/overlay/protocol.rs and portalnet/src/overlay/service.rs
  • several functions (but not all) accept or return Vec<u8>, when it should be either RawContentKey or RawContentValue
• portalnet/src/utp_controller.rs
  • all functions should accept/return bytes::Bytes instead of Vec<u8>
• portalnet/src/utils/portal_wire.rs
  • decode_content_payload - should accept and return bytes::Bytes
• portalnet/src/discovery.rs
  • ProtocolRequest - should be bytes::Bytes
  • send_talk_req - should return bytes::Bytes
• portalnet/src/gossip.rs
  • both propagate_gossip_cross_thread and trace_propagate_gossip_cross_thread should accept RawContentValue instead of Vec<u8>
• trin-storage/src/lib.rs
  • ContentStore::get - should return Result<Option<RawContentValue>>
  • ContentStore::put - should return Result<Vec<(Self::Key, RawContentValue)>, ContentStoreError>
  • all implementations of ContentStore should be updated as well