Add visualization during reconstruction

[bfrosik]

Add means to get 2D slice of the object under reconstruction. Possibly a new trigger.

[jacione]

I've implemented something like this in the CoupledRec class. Would you like me to add it to Rec as well?

[bfrosik]

If it is a new trigger then it can be added in the Rec.

[jacione]

I currently have it just as a toggle. The live plot updates as a part of peak_switch_operation. I'll refactor it into a trigger so that it can be used in either class.

[bfrosik]

That sounds good. As far as the order in the operation flow it can be placed by progress trigger.