grafana/data: PanelTypeChangedHandler API update to use PanelModel instead of panel options object [BREAKING] (#22754)

This changes PanelModel's API to support PanelModel API updates when changing panel type. Primary useful when changing panel type between Angular and React panels, as other migrations can be handled via DashboardMigrator.

API change: https://github.com/grafana/grafana/pull/22754/files#diff-d9e3f91dc7d5697f6d85ada008003b4b