Positive working feedback when loading measure arguments with BCL search

[DavidGoldwasser]

In the OS app you see this when you go first select the measure. It doesn't show anything is happening while the search is going on. You still see "Select Measure to Apply" after choosing one, until search is done.

When adding measure to workflow, the delay occurs when you first take the measure and drop it on the dropzone. It doesn't look like it took. Then when it does show up the arguments are immediately available.

I can demo this at next iteration meeting.

cc: @macumber @evanweaver @asparke2

[macumber]

Apply measure now dialog is also slow, need some measures that have sleep commands in arguments and run to test

[DavidGoldwasser]

@macumber I have slow dialog lunch under issue #163