Cleanup | Remove unused UDT serialization code (#3462)

* Remove _isTopLevelUdt and its usage

This always holds the constant value of true. Code paths which rely on it being false will never be called.

* Remove unused property and fields

IsNullable and _padBuffer were only referenced when _isTopLevelUdt was false.
_nullInstance was only referenced from IsNullable

* Remove _skipNormalize

This was always set to false

* Remove unused parameter from constructor

* Remove needless call to GetFormat

* Remove unused fields

These fields are assigned to, but never used

* Remove unused parameter

SqlConnection.GetBytes output a Format parameter which was never used at its call sites

* Remove incorrect comment

Author: edwardneal

src/Microsoft.Data.SqlClient/netcore/src/Microsoft/Data/SqlClient/SqlConnection.cs

@@ -2547,11 +2547,10 @@ internal object GetUdtValue(object value, SqlMetaDataPriv metaData, bool returnD
             }
         }
 
-        internal byte[] GetBytes(object o, out Format format, out int maxSize)
+        internal byte[] GetBytes(object o, out int maxSize)
         {
             SqlUdtInfo attr = GetInfoFromType(o.GetType());
             maxSize = attr.MaxByteSize;
-            format = attr.SerializationFormat;
 
             if (maxSize < -1 || maxSize >= ushort.MaxValue)
             {

src/Microsoft.Data.SqlClient/netcore/src/Microsoft/Data/SqlClient/TdsParser.cs

@@ -9943,7 +9943,6 @@ private Task TDSExecuteRPCAddParameter(TdsParserStateObject stateObj, SqlParamet
                 {
                     int maxSupportedSize = Is2008OrNewer ? int.MaxValue : short.MaxValue;
                     byte[] udtVal = null;
-                    Format format = Format.Native;
 
                     if (string.IsNullOrEmpty(param.UdtTypeName))
                     {
@@ -9977,7 +9976,7 @@ private Task TDSExecuteRPCAddParameter(TdsParserStateObject stateObj, SqlParamet
                         }
                         else
                         {
-                            udtVal = _connHandler.Connection.GetBytes(value, out format, out maxsize);
+                            udtVal = _connHandler.Connection.GetBytes(value, out maxsize);
                         }
 
                         Debug.Assert(udtVal != null, "GetBytes returned null instance. Make sure that it always returns non-null value");

src/Microsoft.Data.SqlClient/netfx/src/Microsoft/Data/SqlClient/SqlConnection.cs

@@ -2456,11 +2456,10 @@ internal object GetUdtValue(object value, SqlMetaDataPriv metaData, bool returnD
             }
         }
 
-        internal byte[] GetBytes(object o, out Format format, out int maxSize)
+        internal byte[] GetBytes(object o, out int maxSize)
         {
             SqlUdtInfo attr = GetInfoFromType(o.GetType());
             maxSize = attr.MaxByteSize;
-            format = attr.SerializationFormat;
 
             if (maxSize < -1 || maxSize >= ushort.MaxValue)
             {

src/Microsoft.Data.SqlClient/netfx/src/Microsoft/Data/SqlClient/TdsParser.cs

@@ -10139,7 +10139,6 @@ private Task TDSExecuteRPCAddParameter(TdsParserStateObject stateObj, SqlParamet
                 {
                     int maxSupportedSize = Is2008OrNewer ? int.MaxValue : short.MaxValue;
                     byte[] udtVal = null;
-                    Format format = Format.Native;
 
                     if (string.IsNullOrEmpty(param.UdtTypeName))
                     {
@@ -10173,7 +10172,7 @@ private Task TDSExecuteRPCAddParameter(TdsParserStateObject stateObj, SqlParamet
                         }
                         else
                         {
-                            udtVal = _connHandler.Connection.GetBytes(value, out format, out maxsize);
+                            udtVal = _connHandler.Connection.GetBytes(value, out maxsize);
                         }
 
                         Debug.Assert(udtVal != null, "GetBytes returned null instance. Make sure that it always returns non-null value");