Improve HTML views for a few Langfun components.

1) `lf.agentic.ActionInvocation`:
   - Rename `result_metadata` to `metadata` as it's no longer associated with result.
   - Use tab control for rendering action/result/metadata/execution
   - Displaying time badge and usage in "execution" tab header.
   - Auto-select "metadata" or "result" tab when an action is done.
2) `lf.QueryInvocation`:
   - Instrument `start_time` and `end_time`.
   - Add time badge to HTML summary.
   - Select `output` as the default tab.
3) `lf.Template`:
   - Use tabs (template_str, variables) for rendering the HTML view.

PiperOrigin-RevId: 704987034