fix: add default params value for walletInvokeSnap (#126)

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This PR adds a default param values for `walletInvokeSnap`

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packages/site/src/utils/snap.ts

@@ -60,7 +60,7 @@ export const getSnap = async (version?: string): Promise<Snap | undefined> => {
  * @param params - Optional parameters for the method.
  * @returns A promise that resolves to the result of the Snap method invocation.
  */
-const walletInvokeSnap = async (method: string, params?: JSON) => {
+const walletInvokeSnap = async (method: string, params: JSON = {} as JSON) => {
   return await window.ethereum.request({
     method: 'wallet_invokeSnap',
     params: {