update to upstream cose-c

[gocarlos]

I was been doing some changes to cose-c e.g. putting headers in namespace e.g. cose/cose.h, adding namespaced targets e.g. cose-c::cose-c and improving the cmake files...

this means, there are some breaking changes for ot-commissioner, though the effort should be pretty small.

[wgtdkp]

@gocarlos Thanks for your contribution! Currently cose-c branch OT Commissioner is depending on has some additional API, for example:
https://github.com/wgtdkp/COSE-C/blob/059e8f4dbe9827ed89f6731e95052a5a1b79ed94/include/cose.h#L335

But those changes haven't been merged back to the COSE-C master branch, see the PR.

[gocarlos]

upstream seems to compile again after applying cose-wg/COSE-C#93 to current COSE-C master