Make Shop location switcher a component using a global store

Using two switchers (one in the shop nav and the other in the cart) makes possible to have the switcher over the Cart overlay (over intro)

src/style/style.scss

@@ -55,6 +55,7 @@
 @import "molecules/poster";
 @import "molecules/notification-cart";
 @import "molecules/cart-item";
+@import "molecules/shop-locationswitcher";
 
 // Organisms
 @import "organisms/locations";