be able to tag projects as certain modalities in ndstore

[alexbaden]

For example, EM images and LM images get treated differently. I'm not sure what the best way to accomplish this is. Maybe in LIMS, but then we need to be able to handle the case when LIMS isn't available or when the project isn't in LIMS.

One idea would be to add a modality tag to ndstore. The default option would be something like "Unknown" or "Default". Other options would include "EM" and "LM" or "EM" and "AT". NDStore wouldn't necessarily do anything differently, but this would allow me to differentiate between EM and LM data when they're being displayed side-by-side in NDV without storing that data in NDV (there are many cases where you want to treat EM and LM differently when displaying overlays, and the synaptogram service makes no sense with EM projects).

@kunallillaney @jovo @randalburns thoughts?