Set unichain testnet RPC (#714)

Author: bruce-riley

core/base/src/constants/rpc.ts

@@ -88,6 +88,8 @@ const rpcConfig = [[
     ["Rootstock",       "https://public-node.testnet.rsk.co"],
     ["Gnosis",          "https://rpc.chiadochain.net"],
     ["Klaytn",          "https://rpc.ankr.com/klaytn_testnet"],
+    ["Snaxchain",       "https://testnet.snaxchain.io"],
+    ["Unichain",        "https://sepolia.unichain.org"],
   ]], [
   "Devnet", [
     ["Ethereum",  "http://eth-devnet:8545"],