feat(csharp/src/Drivers/Apache/Spark): Perform scalar data type conve…

…rsion for Spark over HTTP (apache#2152)

Adds scalar conversion from string to Date32/Decimal128/DateTimeOff for
DATE/DECIMAL/TIMESTAMP, respectively.

Note:
FLOAT type is returned as Double
NULL type is returned as String.

Re-use existing tests but adjust what data type the comparison uses
depending on the data conversion flag.

Some refactoring to make available from all Hive Server2 driver types.

Add minimal support for Impala testing.

csharp/src/Drivers/Apache/Hive2/DataTypeConversion.cs

@@ -0,0 +1,66 @@
+/*
+* 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.
+*/
+
+using System;
+
+namespace Apache.Arrow.Adbc.Drivers.Apache.Hive2
+{
+    [Flags]
+    internal enum DataTypeConversion
+    {
+        Empty = 0,
+        None = 1,
+        Scalar = 2,
+    }
+
+    internal static class DataTypeConversionParser
+    {
+        internal const string SupportedList = DataTypeConversionOptions.None + ", " + DataTypeConversionOptions.Scalar;
+
+        internal static DataTypeConversion Parse(string? dataTypeConversion)
+        {
+            DataTypeConversion result = DataTypeConversion.Empty;
+
+            if (string.IsNullOrWhiteSpace(dataTypeConversion))
+            {
+                // Default
+                return DataTypeConversion.Scalar;
+            }
+
+            string[] conversions = dataTypeConversion!.Split(',');
+            foreach (string? conversion in conversions)
+            {
+                result |= (conversion?.Trim().ToLowerInvariant()) switch
+                {
+                    null or "" => DataTypeConversion.Empty,
+                    DataTypeConversionOptions.None => DataTypeConversion.None,
+                    DataTypeConversionOptions.Scalar => DataTypeConversion.Scalar,
+                    _ => throw new ArgumentOutOfRangeException(nameof(dataTypeConversion), conversion, "Invalid or unsupported data type conversion"),
+                };
+            }
+
+            if (result.HasFlag(DataTypeConversion.None) && result.HasFlag(DataTypeConversion.Scalar))
+            {
+                throw new ArgumentOutOfRangeException(nameof(dataTypeConversion), dataTypeConversion, "Conflicting data type conversion options");
+            }
+            // Default
+            if (result == DataTypeConversion.Empty) result = DataTypeConversion.Scalar;
+
+            return result;
+        }
+    }
+}