Native Observability 2.0.0

Major release on 1.1.1. The report no longer publishes an invented overhead
percentage summed from four hardcoded constants. The module measures its own
cost on the server it runs on, in paired ON/OFF blocks against a control pass,
and publishes the figure with its source named.

Also: Drupal 12 compatibility, a database asked about window functions instead
of assumed, five capture keys that reject an invalid imported value, and an
uninstall that leaves no tempstore rows behind.

UPGRADE NOTES

- Run `drush updb`. One update hook runs,
  native_observability_report_update_10102.
- The overhead section is set to hidden on every existing site. To publish a
  figure again, measure one with `drush no:overhead:measure --record`, or
  declare one by hand in the report settings.
- Breaking: ObservabilityImpactEstimator and the config and message keys it fed
  are removed. There is no replacement value to migrate to, because the number
  they held was never measured.