Move ColumnKeyValue to the data loader core project (#1770)

Author: ypeckstadt

data-loader/cli/src/main/java/com/scalar/db/dataloader/cli/command/ColumnKeyValueConverter.java

@@ -1,5 +1,6 @@
 package com.scalar.db.dataloader.cli.command;
 
+import com.scalar.db.dataloader.core.ColumnKeyValue;
 import picocli.CommandLine;
 
 /**

data-loader/cli/src/test/java/com/scalar/db/dataloader/cli/command/ColumnKeyValueConverterTest.java

@@ -3,6 +3,7 @@
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 
+import com.scalar.db.dataloader.core.ColumnKeyValue;
 import org.junit.jupiter.api.Test;
 
 class ColumnKeyValueConverterTest {

data-loader/cli/src/main/java/com/scalar/db/dataloader/cli/command/ColumnKeyValue.java renamed to data-loader/core/src/main/java/com/scalar/db/dataloader/core/ColumnKeyValue.java

@@ -1,4 +1,4 @@
-package com.scalar.db.dataloader.cli.command;
+package com.scalar.db.dataloader.core;
 
 /** Represents a key-value pair for a column and its corresponding value. */
 public class ColumnKeyValue {