Previously, Frames could set both these properties along with a
thickness to confusing effect: Most shapes of the same shadowing only
differentiated at a thickness >= 2, and some not at all. This led
to a lot of creative but ultimately superfluous choices in the code.
Instead let's streamline our options, automate thickness, and get
the right look without so much guesswork.
Plain shadowing has been consolidated into a single Plain style,
and 0 thickness can be had by setting style to NoFrame.
This will allow easily adding components such as a search box. Also,
increase the number of emoji per row. This does not fix the issue where
too many emoji will cause the dialog to grow limitlessly, but it looks a
bit more reasonable now with the number of emoji that we have.
