Add Etherscan-style blockie identicon to address detail page

Show a 48px pixelated blockie (same style as Etherscan) centered
above the wallet title on the address detail page. Uses
ethereum-blockies-base64 which generates a base64 PNG from the
address. Replaces the previously added @metamask/jazzicon.

src/popup/index.html

@@ -234,6 +234,10 @@
                 >
                     < Back
                 </button>
+                <div
+                    id="address-jazzicon"
+                    class="flex justify-center mb-2"
+                ></div>
                 <div
                     class="flex justify-between items-center border-b border-border pb-1 mb-2"
                 >