Some basic sidepanel setup

src/backend.js

src/editor/css/editor.css

src/editor/js/components/editor.css

src/editor/js/components/editor.tsx

src/editor/js/components/graphrenderer.css

src/editor/js/components/graphrenderer.tsx

src/editor/js/components/spaceselect.css

src/editor/js/components/spaceselect.tsx

src/editor/js/components/toolbutton.css

src/editor/js/components/toolbutton.tsx

src/editor/js/components/toolpool.css

src/editor/js/components/toolpool.tsx

src/editor/js/state.ts