qr_read_and_tweet nodes for nhm systems

See: https://github.com/strands-project/strands_deployment/issues/38

I extracted this package from a private repository in our github organisation in Lincoln using git subtree. The history is therefore still there and unchanged. If there were commits which included files outside of this package the commit messages will be a bit misleading because it only contains the files belonging to this package.

If I remember correctly @Jailander wanted to clean this up a bit first but since @hawesie wants to try the nhm system I took the liberty of transferring the code to the strands repos.

The package needs `libdmtx-dev` which will be installed via rosdep.