feat(ghverify): emit event when user request verification (#2778)

<!-- please provide a detailed description of the changes made in this
pull request. -->
related to #2777 
<details><summary>Contributors' checklist...</summary>

- [ ] Added new tests, or not needed, or not feasible
- [ ] Provided an example (e.g. screenshot) to aid review or the PR is
self-explanatory
- [ ] Updated the official documentation or not needed
- [ ] No breaking changes were made, or a `BREAKING CHANGE: xxx` message
was included in the description
- [ ] Added references to related issues and PRs
- [ ] Provided any useful hints for running manual tests
- [ ] Added new benchmarks to [generated
graphs](https://gnoland.github.io/benchmarks), if any. More info
[here](https://github.com/gnolang/gno/blob/master/.benchmarks/README.md).
</details>

Co-authored-by: 6h057 <15034695+omarsy@users.noreply.github.com>

examples/gno.land/r/gnoland/ghverify/contract.gno

@@ -83,6 +83,11 @@ func RequestVerification(githubHandle string) {
 	); err != nil {
 		panic(err)
 	}
+	std.Emit(
+		"verification_requested",
+		"from", gnoAddress,
+		"handle", githubHandle,
+	)
 }
 
 // GnorkleEntrypoint is the entrypoint to the gnorkle oracle handler.