Port for afc5bea ([Java]: Provided the ability to access group block length. Enhancement aeron-io#92.)

Author: Olivier Deheurles

main/java/uk/co/real_logic/sbe/generation/csharp/CSharpGenerator.java

@@ -266,6 +266,12 @@ private void generateGroupClassHeader(final StringBuilder sb,
  ));
 
  sb.append(String.format(
+ indent + " public const int BlockLength = %d;\n",
+ blockLength
+ ));
+
+ sb.append(String.format(
+ indent + " public int ActingBlockLength { get { return BlockLength; } }\n\n" +
  indent + " public int Count { get { return _count; } }\n\n" +
  indent + " public bool HasNext { get { return _index + 1 < _count; } }\n\n"
  ));