Automatically generate manual flag text in processing viewer

[wmay]

The current manual flagging workflow requires me to add entries to a csv file, then reprocess the data to check that the flag was entered correctly. This can be frustrating due to entry errors and the hassle of reprocessing data repeatedly. This could be made easier by having the viewer app generate the csv entry and display the proposed flag on the current plot.

[RB-ASRC]

I'm not sure what flagging this is about, if there is anything I can do on the operator end to help let me know.

[wmay]

I don't think there's anything you can do at the moment-- I just want remove some data entry hassles for myself.

If you're interested maybe you could send pull requests to add manual flags for Whiteface data, but I need to get a little more organized before talking about that.