Compilable example for asn1c extensible defect

See vlm/asn1c#433

In proto/CMakeLists.txt one of the three asn1c versions can be selected for the test.

1. Run ./build_asn1c_versions.sh
2. Select one of the three asn1c versions in proto/CMakeLists.txt
3. Run ./build_and_run.sh
4. Compare the hex output

Valid:   010100000539007b0802d693a409ad27480c01001401861a9fc000420008a8
Invalid: 010100000539007b0802d693a409ad27480c01001401861a9fc00084001150

5. Repeat from 2. with another asn1c version