This commit converts the `AdminReport` component, which is quite
high complexity, to gjs. After this initial round, ideally this
component would be broken up into smaller components because it is
getting quite big now.
Also in this commit:
* Add an option to display the report description in a tooltip, which
was
the main way the description was shown until recently. We want to use
this on the dashboard view mostly.
* Move admin report "mode" definitions to the server-side Report model,
inside a `Report::MODES` constant, collecting the modes defined in
various
places in the UI into one place
* Refactor report code to refer to mode definitions
* Add a `REPORT_MODES` constant in JS via javascript.rake and refactor
JS to refer to the modes
* Delete old admin report components that are no longer used
(trust-level-counts, counts, per-day-counts) which were replaced
by admin-report-counters a while ago
* Add a new `registerReportModeComponent` plugin API, some plugins
introduce their own modes (like AI's `emotion`) and components and
we need a way to render them
