Config in beacon

Closes #27 (closed) #29 (closed) ui/daiquiri-tomo#256 (closed)

This PR apply the proposal from #27 (closed)

There is probably fixes to be done for the different mapping according to the used version of the data policy.

And it would be good to add a test, if possible.

Here is an example to update the config in beamline: ui/daiquiri-tomo@d03e99ba