add hfnet cpp ros inference module

[TurtleZhong]

No description provided.

[sarlinpe]

Hi!
Thank you so much for your contribution. It's great that you managed to integrate HF-Net into an actual pipeline - I am sure that many will find this valuable! For the sake of clarity, and because I don't have time to test this PR, I think that hfnet_ros should remain a separate repo and not be merged here. I do not plan to actively maintain the HF-Net codebase, partly because it is outdated and the hloc toolbox is much easier to work with. Our recent combo hloc+SuperGlue is surely more computationally expensive than HF-Net, but I think that focusing on improving the accuracy over the runtime is the right thing to do.

[TurtleZhong]

ok,Thanks any way. I guess just leave the hfnet_ros package along. hloc+SuperGlue is also a great project, I am studying it recently. The localization Accuracy is very important, but I wanna transfer the work to real application, and test it in our own framework, For the real application, the fusion is needed, We can combine the hfnet/hloc results with IMU/Odom/GPS to get a better results.