Add toString in tarantool proxy entities

Closes #406

Author: ArtDu

src/main/java/io/tarantool/driver/core/TarantoolResultImpl.java

@@ -158,4 +158,11 @@ public ListIterator<T> listIterator(int index) {
     public List<T> subList(int fromIndex, int toIndex) {
         return this.tuples.subList(fromIndex, toIndex);
     }
+
+    @Override
+    public String toString() {
+        return "TarantoolResultImpl{" +
+            "tuples=" + tuples +
+            '}';
+    }
 }

src/main/java/io/tarantool/driver/core/metadata/TarantoolFieldMetadataImpl.java

@@ -65,4 +65,14 @@ public int getFieldPosition() {
     public boolean getIsNullable() {
         return isNullable;
     }
+
+    @Override
+    public String toString() {
+        return "TarantoolFieldMetadataImpl{" +
+            "fieldName='" + fieldName + '\'' +
+            ", fieldType='" + fieldType + '\'' +
+            ", fieldPosition=" + fieldPosition +
+            ", isNullable=" + isNullable +
+            '}';
+    }
 }

src/main/java/io/tarantool/driver/core/tuple/TarantoolFieldImpl.java

@@ -100,4 +100,9 @@ public boolean equals(Object o) {
     public int hashCode() {
         return Objects.hash(value);
     }
+
+    @Override
+    public String toString() {
+        return value.toString();
+    }
 }

src/main/java/io/tarantool/driver/core/tuple/TarantoolTupleImpl.java

@@ -1,21 +1,5 @@
 package io.tarantool.driver.core.tuple;
 
-import io.tarantool.driver.api.metadata.TarantoolSpaceMetadata;
-import io.tarantool.driver.api.tuple.TarantoolField;
-import io.tarantool.driver.api.tuple.TarantoolNullField;
-import io.tarantool.driver.api.tuple.TarantoolTuple;
-import io.tarantool.driver.exceptions.TarantoolClientException;
-import io.tarantool.driver.exceptions.TarantoolSpaceFieldNotFoundException;
-import io.tarantool.driver.mappers.MessagePackMapper;
-import io.tarantool.driver.mappers.MessagePackObjectMapper;
-import io.tarantool.driver.utils.Assert;
-import org.msgpack.core.MessagePack;
-import org.msgpack.core.MessagePackException;
-import org.msgpack.core.MessagePacker;
-import org.msgpack.core.MessageUnpacker;
-import org.msgpack.value.ArrayValue;
-import org.msgpack.value.Value;
-
 import java.io.IOException;
 import java.math.BigDecimal;
 import java.time.Instant;
@@ -31,6 +15,23 @@
 import java.util.UUID;
 import java.util.function.Consumer;
 
+import org.msgpack.core.MessagePack;
+import org.msgpack.core.MessagePackException;
+import org.msgpack.core.MessagePacker;
+import org.msgpack.core.MessageUnpacker;
+import org.msgpack.value.ArrayValue;
+import org.msgpack.value.Value;
+
+import io.tarantool.driver.api.metadata.TarantoolSpaceMetadata;
+import io.tarantool.driver.api.tuple.TarantoolField;
+import io.tarantool.driver.api.tuple.TarantoolNullField;
+import io.tarantool.driver.api.tuple.TarantoolTuple;
+import io.tarantool.driver.exceptions.TarantoolClientException;
+import io.tarantool.driver.exceptions.TarantoolSpaceFieldNotFoundException;
+import io.tarantool.driver.mappers.MessagePackMapper;
+import io.tarantool.driver.mappers.MessagePackObjectMapper;
+import io.tarantool.driver.utils.Assert;
+
 /**
  * Basic Tarantool tuple implementation
  *
@@ -140,7 +141,7 @@ public TarantoolTupleImpl(ArrayValue value, MessagePackMapper mapper, TarantoolS
     @Override
     public boolean hasMetadata() {
         return spaceMetadata != null && spaceMetadata.getSpaceFormatMetadata() != null &&
-                   !spaceMetadata.getSpaceFormatMetadata().isEmpty();
+            !spaceMetadata.getSpaceFormatMetadata().isEmpty();
     }
 
     @Override
@@ -467,4 +468,13 @@ private void readObject(java.io.ObjectInputStream in) {
             }
         }
     }
+
+    @Override
+    public String toString() {
+        return String.format(
+            "\nTarantoolTupleImpl{\n" +
+                "\tspaceMetadata=%s,\n" +
+                "\tfields=%s\n" +
+            "}", spaceMetadata, fields);
+    }
 }