refactor(telemetry): Update code suggestion telemetry

Solves: https://gitlab.com/gitlab-org/gitlab-vscode-extension/-/issues/1024 and gitlab-org/modelops/applied-ml/code-suggestions/ai-assist#297 (closed)

This MR update code suggestion telemetry with new context version and changes moment when suggestion_requested event is triggered to avoid orphaned suggestions being reported when code suggestion prompt is rejected.