sdllc/bertconsole

BERT Shell 3

New console for BERT, replacing the old one.

This is not a complete rewrite, but it's not a branch. Some core parts were rewritten and then we bolted on some code from the old one. It would have been impractical to branch because some of the lowest-level stuff was changed (in particular, settings management).

The new editor is built on monaco, and this was the driving factor in the rewrite. We could not get indenting to work satisfactorily in Codemirror and this was driving me crazy. CM is still there, though, in the shell, so it's still a dependency. Material icons were dropped in favor of just using unicode characters. It turns out unicode characters render differently on different versions of Windows (!) so we need to go back to icons. We're using a custom set to keep it small.

Build drops webpack entirely, as there's no real reason to use it, and this simplifies file layout.

As regards the larger BERT application, this should be a drop-in replacement, although it will lose any old settings (because the layout of settings has changed a bit).