Add unit tests for OutputHelper class (#1084)

* Add unit tests for OutputHelper class

* add copyright header

* Make OutputHelperTest package-private

* Make OutputHelper methods package-private

* Update OutputHelperTest to use LinkedHashMap for predictable order

cli/harness/src/test/java/io/helidon/build/cli/harness/OutputHelperTest.java

@@ -0,0 +1,57 @@
+/*
+ * Copyright (c) 2024 Oracle and/or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package io.helidon.build.cli.harness;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.LinkedHashMap;
+import java.util.Map;
+
+import static org.hamcrest.CoreMatchers.is;
+import static org.hamcrest.MatcherAssert.assertThat;
+
+class OutputHelperTest {
+
+    @Test
+    void testTable() {
+        Map<String, String> map = new LinkedHashMap<>();
+        map.put("key1", "value1");
+        map.put("key2", "value2");
+        String expected = "  key1    value1\n  key2    value2";
+        assertThat(OutputHelper.table(map), is(expected));
+    }
+
+    @Test
+    void testTableWithMaxKeyWidth() {
+        Map<String, String> map = new LinkedHashMap<>();
+        map.put("key1", "value1");
+        map.put("key2", "value2");
+        String expected = "  key1    value1\n  key2    value2";
+        assertThat(OutputHelper.table(map, 4), is(expected));
+    }
+
+    @Test
+    void testMaxKeyWidth() {
+        Map<String, String> map1 = new LinkedHashMap<>();
+        map1.put("key1", "value1");
+        map1.put("longerKey", "value2");
+        Map<String, String> map2 = new LinkedHashMap<>();
+        map2.put("short", "value3");
+        map2.put("longestKey", "value4");
+        int expected = 10; // length of "longestKey"
+        assertThat(OutputHelper.maxKeyWidth(map1, map2), is(expected));
+    }
+}