Convert the files in the micro directory to TypeScript

[jbphet]

In #99, much of the codebase was converted to TypeScript. The files for the "Micro" screen were omitted from this initial conversion because we're not planning to release it for a while, because it is quite independent from the other three screens, and I need to make progress on the other three screens soon.

I'm going to put a reminder on my calendar for a couple of months from now to start on this in a "chip away" sort of fashion. Hopefully, I'll be further along with the other screens by then, and some of the big-picture question on things like option patterns will be worked out.

[jbphet]

Update: I'm going to continue to defer this a while longer. At the moment, the other code has been converted to TS, but there are a number of things still to be done, such as converting all of the enumerations and options patterns. Once this is all done, we can start to consider converting this code.