Port an existing maze game, as an demonstrative example

[matthewhammer]

Originally from experiments here, in this PR

[matthewhammer]

The maze game is adapted enough to expose a limitation in the ic-game-terminal implementation of the render types in package redraw.

Namely, need to implement text element, and perhaps some built-in text glyphs to make simple server canisters easier to write. Can take more code from ZQM to start these extensions.

Will do those fixes in subsequent PRs.