'Apply tags' should have an action driven blank state

Currently when you have no tags, the only way to add tags appears to be from within a card itself. Yet in card view, "Apply tags" still shows up when there are no tags to apply, and has an empty dropdown when you click on it.

I'd propose a couple things:

- Change the dropdown to just 'Tags'

- Add an action to 'Create new tag' to the dropdown that would exist either at the end of the list, or stickied to the bottom of it, with tags scrolling above it (preferred)

- And when there are no tags, you would have the dropdown say "You don't currently have any tags" and prompt to create one from the action that now exists in the dropdown.

- Furthermore, this would allow you to filter by tags vs just applying them, and allow you to apply them by selecting them, the way that add to stack shows up when cards are selected.