Evaluate dropdown-based tag UX

[nathanielrindlaub]

We need more user feedback before making any decisions on this, but there may be room for improvement in the UX for adding Tags to images. The first iteration is essentially a dropdown menu that lives below the full size image in the Loupe, which means applying one is a two-step process of clicking the menu to open it and then selecting the tag you want to apply. While that's fine for rarely-used tags, for example annotating an image as a "depredation event", but it's going to be really inefficient if for use cases like "seen" in which users want to add tags to a lot of images quickly.

One idea would be to populate the tag toolbar with the available tags in a "suggested" or "checked-off" state, so that users could just click on them directly to apply them w/o having to open a menu. Perhaps we do both and keep the menu but add a "toolbar display" option to Project Tags so users can surface their most frequently used tags to the UI, but not clutter it with rarely used ones?

Regardless, adding hotkeys and an "add tag" item to the multi-select context menu will help make tag application significantly more efficient without changing the current dropdown UI, so we should probably start there before assessing whether or not to move forward on this.