Add "use Spotlight" to SDK verify steps

[BYK]

Instead of asking people to throw an exception and wait till they see it on their prod Sentry instance, we can ask them to launch spotlight, set $SENTRY_SPOTLIGHT=1 and watch it in Spotlight in realtime. This would also verify tracing and distributed tracing setups too.

The only caveat is, it wouldn't cover if you put your DSN incorrectly.

[BYK]

Since we already run sentry-wizard through npx, it makes sense to add npx @spotlightjs/spotlight as a final step with SENTRY_SPOTLIGHT=1 to verify the setup. This is especially useful for projects with distributed tracing.