📈 Fix telemetry overcounting and reduce event volume

[savannahostrowski]

Closes https://github.com/fastapilabs/cloud/issues/3952

This PR fixes a couple things to prevent overcounting of events:

• Previously, we didn't seed the lastAuthState before polling which caused us to fire a spurious extension_cloud_sign_in on every activation for already-signed-in users. Now we seed lastAuthState from the current token state before starting the poll, so only real sign-in transitions fire the event.
• Previously, we were tracking whether we were providing codelens to the user. This event was noisy and ultimately, unused. I've opted to remove it. We still track when a codelens was clicked, which IMO is a better signal anyway.
• Previously, we were tracking whether we were able to detect an entrypoint as a distinct event. This was also pretty noisy due to reloads. Instead, we can fold the detection-method counts (detection_method_config/pyproject/heuristic) and folders_with_apps into extension_activated properties.