improve(JSONUtils): Handle BigInt on JSON stringification (#733)

This is one prerequisite for trialing ethers v6 and viem in the bots.

src/utils/JSONUtils.ts

@@ -53,7 +53,7 @@ export function jsonReplacerWithBigNumbers(_key: string, value: unknown): unknow
   // We need to check if this is a big number, because the JSON parser
   // is not aware of BigNumbers and will convert them to the string representation
   // of the object itself which is not what we want.
-  if (BigNumber.isBigNumber(value)) {
+  if (BigNumber.isBigNumber(value) || typeof value === "bigint") {
     return value.toString();
   }
   // There's a legacy issues that returns BigNumbers as { type: "BigNumber", hex: "0x..." }