UI should scale to fill more of the screen #38
Description
Currently the UI doesn't use space very efficiently, and is having its size set by px widths and heights. I think it'll be easier to iterate on the client UI layout if we do something like cssgrid fractions (fr), and viewport units (vh, vw).
The wrinkle to this that I'm not sure offhand how to resolve is that the canvas rendered game view will need to maintain its aspect. Right now the aspect is set via the width and height of the canvas, and the scaling of tiles in the canvas is calculated based on those values. It could be that the aspect could be recalculated, or maybe there is a cleaner all-around solution