Fix Shop issues

- Move ButtonCart from nav to position it on top right
- ButtonCart amount indicator position (center left => top left)
- Bring back updating label when changing cart (+ other transitions)
- Make ShopHeader picture gradient a bit bigger

src/components/organisms/Cart.svelte

@@ -150,7 +150,7 @@
                     />
                 {/each}
             {:else}
-                <div class="cart__empty shadow-small">
+                <div class="cart__empty shadow-small" transition:fade={{ duration: 600 }}>
                     <div class="icon">
                         <Icon icon="bag" label="Shopping bag icon" />
                     </div>
@@ -159,7 +159,10 @@
             {/if}
 
             {#if !$cartData || $cartIsUpdating}
-                <div class="cart__update" transition:fade={{ duration: 400 }}>
+                <div class="cart__update"
+                    in:fly={{ y: -4, duration: 600, easing: quartOut }}
+                    out:fly={{ y: 4, duration: 600, easing: quartOut }}
+                >
                     <p>Updating…</p>
                 </div>
             {/if}