Add CPM (TS102894-2v211) to Vanetza

[diogopjesus]

Hi @riebl, This is a continuation of the old pull request i made. I deleted it by mistake when moving the code to another branch. I am sorry about the inconvenience. This implementation already has the newly released CAM and the release 2 of DENM, besides the CPM. To support either ITS release 1 or ITS release 2, i have changed the cmake recipe to support an option (VANETZA_ASN1_WITH_ITS2) that only links the selected version. The vanetza/asn1/its was renamed to vanetza/asn1/its1 and now the files of the selected release are copied into vanetza/asn1/its. There might be a more effiecient way to do it, let me know your thoughts. A version of the asn1c proposed in this issue by @v0-e was used. This version supports the compilation of the release 2 asn1 files without any patching. The only small change i made was on the import CDD identification on both the CPM and DEMN to the CDDv2.2.1. Finally some files, due to differences in the release 1 to release 2 specification, were changed in order to support both releases (like the cpm.hpp). With that said, some files, like tests, still need to changed in order to fully support both releases. Looking forward to receive some feedback.

[riebl]

I will have a deeper look at it as soon as possible. But I can say already now: Thanks a lot for your effort! Obviously, some GitHub unit tests fail at the moment which needs to be fixed.

[riebl]

Sorry, I had no chance yet to review your PR carefully and I will be abroad for a week now. I have to postpone the review until my return.