Remove or reactivate polling code for voxelytics workflow viewer

[fm3]

Currently the polling interval is set to null, which then needs to be handled by the polling code.

Apparently, this was set to avoid excessive load for the server. We should determine if the load would again be as high with the current server code. If no, consider re-enabling the automatic polling. If yes, remove all the polling code. To not have this dead code lying around.