Add id to events and tests

Author: adriaandotcom

src/default.js

@@ -1011,6 +1011,7 @@
       if (event) {
         sendData(
           assign(eventParams, {
+            id: uuid(),
             query: getQueryParams(!firstPage),
             referrer:
               (firstPage || sameSite) && collectMetricByString("r")

test/test-events.js

@@ -42,8 +42,14 @@ module.exports = async ({ os, browser }) => {
       "page_id",
       "session_id",
       "type",
+      "id",
     ]);
 
+    expect(
+      UUIDvalidate(request.body.id, 4),
+      "event id should be a valid UUIDv4"
+    ).to.be.true;
+
     expect(
       UUIDvalidate(request.body.session_id, 4),
       "session_id should be a valid UUIDv4"