Refactor: CSS handling (#2344)

* refactor(css): only load base styles, add css task, cleanup exports
* style(base): add edge label bg
* refactor(css): use css-utils
* feat(core): add Panel component
* refactor(background): cleanup
* refactor(css-handling): cleanup

packages/controls/src/index.tsx

@@ -1,3 +1,3 @@
-export { default as default } from './Controls';
+export { default as Controls } from './Controls';
+export { default as ControlButton } from './ControlButton';
 export * from './types';
-export * from './Controls';