[Hans] Dynamic Change to scan decision labels

[curtislisle]

It was requested during our meeting with Hans, that it would be helpful to be able to add a new scan decision label dynamically. The example given was after a project is created and some scans are reviewed, the study designer thinks, "I wish I had built the project with this keyword". Then an additional scan decision label could be added without having to re-initialize the project. This way the previous scans could be revisited to add that annotation for any scans it applies to.