* Revert "Revert "Update to new Snackbar component and notice store""
* Update uploader component to use createNotice
* Bump required WP version to 5.2
* Update required PHP and WP versions in plugin header
* Add new wordpress/components version and fix dependencies
* Add in snackbar styling and gutenberg variables
* Convert all existing notice actions to wordpress/notices
* Fix linting errors
* Add package.lock changes
* Update search list control snapshots with new attributes
* Fix Summary values not visible with IE11
* Fix Summary grid for IE11
* Move grid position mixin to _mixins file, so it can be used for other elements
* Remove set-grid-positions mixin and improve code understandability
* Move non-reset SCSS to a new file
* Split shared files and “meta” files into two folders
This also creates two new base scss files for the different app vs embedded CSS files
* Move notice & embed-specific css out of reset
* Update README with folder structure notes