* Initial factoring out of parts of the LayerUI component
2360 → 2224 LOC
* Create a Section component
* Break up src/index.tsx
* Refactor actions to reduce duplication, fix CSS
Also consolidate icons
* Move scene/data.ts to its own directory
* Fix accidental reverts, banish further single-character variables
* ACTIVE_ELEM_COLOR → ACTIVE_ELEMENT_COLOR
* Further refactoring the icons file
* Log all errors
* Pointer Event polyfill to make the tests work
* add test hooks & fix tests
Co-authored-by: dwelle <luzar.david@gmail.com>
