ARROW-259: Use Flatbuffer Field type instead of MaterializedField

Remove MaterializedField, MajorType, RepeatedTypes

Add code to convert from FlatBuf representation to Pojo

also adds tests to test the conversion

format/Message.fbs

@@ -1,10 +1,13 @@
-namespace apache.arrow.flatbuf;
+namespace org.apache.arrow.flatbuf;
 
 /// ----------------------------------------------------------------------
 /// Logical types and their metadata (if any)
 ///
 /// These are stored in the flatbuffer in the Type union below
 
+table Null {
+}
+
 /// A Tuple in the flatbuffer metadata is the same as an Arrow Struct
 /// (according to the physical memory layout). We used Tuple here as Struct is
 /// a reserved word in Flatbuffers
@@ -45,10 +48,22 @@ table Decimal {
   scale: int;
 }
 
+table Date {
+}
+
+table Time {
+}
+
 table Timestamp {
   timezone: string;
 }
 
+table IntervalDay {
+}
+
+table IntervalYear {
+}
+
 table JSONScalar {
   dense:bool=true;
 }
@@ -58,13 +73,18 @@ table JSONScalar {
 /// add new logical types to Type without breaking backwards compatibility
 
 union Type {
+  Null,
   Int,
   FloatingPoint,
   Binary,
   Utf8,
   Bool,
   Decimal,
+  Date,
+  Time,
   Timestamp,
+  IntervalDay,
+  IntervalYear,
   List,
   Tuple,
   Union,

header

@@ -0,0 +1,16 @@
+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.
+