Deps: Include UA-NodeSet repo as git-submodule

[GoetzGoerisch]

No description provided.

[AndreasHeine]

https://github.com/AndreasHeine/SampleServer-node-opcua/projects/1#card-76005527

guess we need that so you only have the nodeset-filename in configuration !?

[GoetzGoerisch]

Would love to pull the released companion specifications directly from the OPCF repo. But I'm going to look into the mechanism @erossignon has build in for the base node set.

[AndreasHeine]

would be:

instead of:

then you lose a little control on the versions? if intended i am fine with it!

if we use a submodule we need to figure some how out what to import and more importantly what not or the path in config gets longer.