Converting this controller to TypeScript furthers the goal of getting
this whole codebase converted, of course, but it also helps in comparing
the differences between this version of the NetworkController and the
version in the `core` repo more easily, which will ultimately help us in
coalescing the two implementations.
Co-authored-by: Mark Stacey <markjstacey@gmail.com>
Co-authored-by: legobeat <109787230+legobeat@users.noreply.github.com>