Feat: Make protocol "inspectable"

[hmoog]

This PR uses the newly introduced runtime inspection framework, to make the protocol "inspectable" (list all reachable objects and their relations).

We should most probably extend the inspectability of our data structures to the engine but this can happen in a separate PR.

A call to fmt.Println(protocol.Inspect()) produces the following output:

Protocol(node0) {
  Commitments {
    Root: Commitment(Slot93.0) {
      Parent: nil,
      MainChild: Commitment(Slot94.0) {
        Parent: Commitment(Slot93.0) {...},
        MainChild: Commitment(Slot95.0) {
          Parent: Commitment(Slot94.0) {...},
          MainChild: Commitment(Slot96.0) {
            Parent: Commitment(Slot95.0) {...},
            MainChild: Commitment(Slot97.0) {
              Parent: Commitment(Slot96.0) {...},
              MainChild: Commitment(Slot98.0) {
                Parent: Commitment(Slot97.0) {...},
                MainChild: nil,
                Chain(0) {
                  ForkingPoint: Commitment(Slot93.0) {...},
                  ParentChain: nil,
                  ChildChains: Set(0xc000ade000) {}
                },
                Children: Set(0xc001a0d850) {}
              },
              Chain(0) {...},
              Children: Set(0xc001221a70) {
                Commitment(Slot98.0) {...}
              }
            },
            Chain(0) {...},
            Children: Set(0xc0015c4c90) {
              Commitment(Slot97.0) {...}
            }
          },
          Chain(0) {...},
          Children: Set(0xc00166cc70) {
            Commitment(Slot96.0) {...}
          }
        },
        Chain(0) {...},
        Children: Set(0xc001394e80) {
          Commitment(Slot95.0) {...}
        }
      },
      Chain(0) {...},
      Children: Set(0xc000d99910) {
        Commitment(Slot94.0) {...}
      }
    },
    Set(0xc000119580) {
      Commitment(Slot93.0) {...},
      Commitment(Slot94.0) {...},
      Commitment(Slot95.0) {...},
      Commitment(Slot96.0) {...},
      Commitment(Slot97.0) {...},
      Commitment(Slot98.0) {...}
    },
    cachedRequests: ShrinkingMap(0xc0000c25d0) {
      CommitmentID(0xac99cb18c5e30fad82ae63a99a020d6f94db03e79c18b23601e9efd78f78f22a5e000000:94): Commitment(Slot94.0) {...},
      CommitmentID(0x6e6d603e8634a243502fb118e42589211505983373dd65e83fa7aec3f21092af5f000000:95): Commitment(Slot95.0) {...},
      CommitmentID(0x576800523388af62c4fcf413f9a9b6591bc0ac4dde7ce9928984020c5f6f6e7460000000:96): Commitment(Slot96.0) {...},
      CommitmentID(0xd2196cc23ba098202d4cd2927c41c6a297debf81ebef2e7aed5fe08f6ed2211a61000000:97): Commitment(Slot97.0) {...},
      CommitmentID(0xd4857903ea5f0a93fb48b23bc8a639dfb7709a42c5e1aac6cf5ead9b6255c8c062000000:98): Commitment(Slot98.0) {...},
      CommitmentID(0x417fcaa633f57401fbecd899e21638a635102580d57ae02891c4f9a4939722ae5d000000:93): Commitment(Slot93.0) {...}
    }
  },
  Chains {
    Main: Chain(0) {...},
    HeaviestClaimedCandidate: nil,
    HeaviestAttestedCandidate: nil,
    Set(0xc000119d80) {
      Chain(0) {...}
    }
  }
}