Add support for newer cmake versions (and their policies)

[leonardocarreras]

This PR adds:

• A check for CUDA language availability in CMakeLists of the main villlas-node
• Changes the hardcoding of a path in for villas-fpga (in gpu)

This gives some errors related to CMP0146 and CMP0104 in newer CMake versions

This is needed in sogno-platform/dpsim#334 (was tested locally)

[leonardocarreras]

The CI is not fully working (does not pull the images for the tests, for example for mosquitto)

[stv0g]

Hey @n-eiling,

do you want to review this change as well? Are you still working with VILLASnode? Or do you want to be removed from the CODEOWNERS file for future PRs?

[stv0g]

Hey @leonardocarreras,

lets wait until the end of the week and otherwise merge it :)

[n-eiling]

I don't think the GPU code is working right now. As far as I know, nobody has used it in a long time. I wouldn't be opposed to removing it.

[leonardocarreras]

@n-eiling thanks for the feedback, it is still giving some errors even with this... If removing is also a reasonable option then is a good future step, gdrcopy also brings problems

[stv0g]

Do we then rip-out all the GPU related stuff?

[n-eiling]

It's not that deeply integrates, or is it? If it's not too much trouble, I think removing it is a good idea.

[leonardocarreras]

I can attempt a PR to remove the GPU stuff this week. I assume if it works, in that case this PR will not be needed...

[leonardocarreras]

Closing now, not needed due to #908