* Switch code editor to Monaco

This switches out CodeMirror for Monaco which is based on the same code
base as VS code and should work pretty similar to it.

It does add a few async chunks, totalling around 10MB to our build. It
currently supports around 65 languages and in the default configuration,
each language would emit one ugly [number].js chunk, so I opted to
combine them all into a single file for now.

CodeMirror is still being used under the hood by SimpleMDE so it can not
be removed yet.

* inline editorconfig, fix diff, use for markdown, remove more dead code

* refactors, remove jquery usage

* use tab_width

* fix intellisense

* rename function for clarity

* misc tweaks, enable webpack progress display

* only use --progress on dev build

* remove useless borders in arc-green

* fix typo

* remove obsolete comment

* small refactor

* fix file creation and various refactors

* unset useTabStops too when no editorconfig

* small refactor

* disable webpack's [big] warnings

* remove useless await

* fix dark theme check

* rename chunk to 'monaco'

* add to .gitignore and delete webpack dest before build

* increase editor height

* support more editorconfig properties

* remove empty element filter

* rename

Co-authored-by: John Olheiser <john.olheiser@gmail.com>