Allow more than 32K prepared statement parameters.

Author: bgrainger

src/MySqlConnector/Protocol/Payloads/StatementPrepareResponsePayload.cs

@@ -14,8 +14,8 @@ public static StatementPrepareResponsePayload Create(ReadOnlySpan<byte> span)
 			var reader = new ByteArrayReader(span);
 			reader.ReadByte(0);
 			var statementId = reader.ReadInt32();
-			var columnCount = (int) reader.ReadInt16();
-			var parameterCount = (int) reader.ReadInt16();
+			var columnCount = (int) reader.ReadUInt16();
+			var parameterCount = (int) reader.ReadUInt16();
 			reader.ReadByte(0);
 			var warningCount = (int) reader.ReadInt16();