Tidy of components

- Moved all components into a single directory like nextjs
 - Made component names consistent with each other
 - Made component names consistent with their export class names
 - Added storybook for a few components with the aim to extend this further.

.storybook/maputnik.theme.js

@@ -0,0 +1,8 @@
+import { create } from '@storybook/theming/create';
+
+export default create({
+  base: 'light',
+
+  brandTitle: 'Maputnik',
+  brandUrl: 'https://github.com/maputnik/editor',
+});