PARQUET-2075: Implement ParquetRewriter

 - A new ParquetRewriter is introduced to unify rewriting logic.
 - RewriteOptions is defined to provide essential settings.
 - CompressionConverter, ColumnPruner, and ColumnMasker have been refactored.

parquet-hadoop/src/main/java/org/apache/parquet/hadoop/rewrite/MaskMode.java

@@ -0,0 +1,45 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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 org.apache.parquet.hadoop.rewrite;
+
+public enum MaskMode {
+  NULLIFY("nullify"),
+  HASH("hash"),
+  REDACT("redact");
+
+  private String mode;
+
+  MaskMode(String text) {
+    this.mode = text;
+  }
+
+  public String getMode() {
+    return this.mode;
+  }
+
+  public static MaskMode fromString(String mode) {
+    for (MaskMode b : MaskMode.values()) {
+      if (b.mode.equalsIgnoreCase(mode)) {
+        return b;
+      }
+    }
+    return null;
+  }
+
+}