feat: add Etherscan explorer to Sonic (#7927)

Co-authored-by: ligi <ligi@ligi.de>

Author: fubuloubu

_data/chains/eip155-146.json

@@ -19,6 +19,12 @@
   "networkId": 146,
   "icon": "sonic",
   "explorers": [
+    {
+      "name": "etherscan",
+      "url": "https://sonicscan.org",
+      "icon": "sonic",
+      "standard": "EIP3091"
+    },
     {
       "name": "sonic",
       "url": "https://explorer.soniclabs.com",