Beefy data structure definition and implementation

src/main/java/com/limechain/beefy/dto/BeefyPayloadId.java

@@ -0,0 +1,24 @@
+package com.limechain.beefy.dto;
+
+public enum BeefyPayloadId {
+    MMR(new byte[]{'m', 'h'});
+
+    private final byte[] id;
+
+    BeefyPayloadId(byte[] id) {
+        this.id = id;
+    }
+
+    public byte[] getId() {
+        return id;
+    }
+
+    public static BeefyPayloadId fromBytes(byte[] bytes) {
+        for (BeefyPayloadId value : values()) {
+            if (java.util.Arrays.equals(value.id, bytes)) {
+                return value;
+            }
+        }
+        throw new IllegalArgumentException("Unknown BeefyPayloadId: " + java.util.Arrays.toString(bytes));
+    }
+}

src/main/java/com/limechain/beefy/dto/Commitment.java

@@ -0,0 +1,13 @@
+package com.limechain.beefy.dto;
+
+import lombok.Data;
+
+import java.math.BigInteger;
+import java.util.List;
+
+@Data
+public class Commitment {
+    private List<PayloadElement> payload;
+    private BigInteger blockNumber;
+    private BigInteger validatorSetId;
+}

src/main/java/com/limechain/beefy/dto/PayloadElement.java

@@ -0,0 +1,9 @@
+package com.limechain.beefy.dto;
+
+import lombok.Data;
+
+@Data
+public class PayloadElement {
+    private BeefyPayloadId payloadId;
+    private byte[] data;
+}

src/main/java/com/limechain/beefy/dto/SignedCommitment.java

@@ -0,0 +1,13 @@
+package com.limechain.beefy.dto;
+
+import com.limechain.runtime.hostapi.dto.Signature;
+import lombok.Data;
+
+import java.util.List;
+import java.util.Optional;
+
+@Data
+public class SignedCommitment {
+    private Commitment commitment;
+    private List<Optional<Signature>> signature;
+}

src/main/java/com/limechain/beefy/dto/ValidatorSet.java

@@ -0,0 +1,12 @@
+package com.limechain.beefy.dto;
+
+import io.libp2p.core.crypto.PubKey;
+import lombok.Data;
+
+import java.util.List;
+
+@Data
+public class ValidatorSet {
+    private List<PubKey> validators;
+    private long id;
+}

src/main/java/com/limechain/beefy/dto/VoteMessage.java

@@ -0,0 +1,13 @@
+package com.limechain.beefy.dto;
+
+import com.limechain.runtime.hostapi.dto.Signature;
+import lombok.Data;
+
+import java.math.BigInteger;
+
+@Data
+public class VoteMessage {
+    private Commitment commitment;
+    private BigInteger authorityId;
+    private Signature signature;
+}