* Add Drawer component
* Use element dataset instead of a window global
* Rename miniCartOverlay to miniCartDrawerPlaceholder
* Refactor styles so screen overlay covers the entire screen
* Use rem instead of em for the drawer title size to keep it consistent between renders
* Keep focus when replacing the mini cart button
* Match overlay colors from designs
* Use is-loading class like several other blocks
* Add more doc comments
* Don't listen to clicks on Mini Cart button when it's open
* Update Drawer component styles
Albert Juhé Lluveras