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.

package.json

@@ -20,6 +20,7 @@
         "tailwindcss": "^4.2.1"
     },
     "dependencies": {
+        "ethereum-blockies-base64": "^1.0.2",
         "ethers": "^6.16.0",
         "libsodium-wrappers-sumo": "^0.8.2",
         "qrcode": "^1.5.4"