doc: update stability of report features

This commit updates the stability documentation for the report
feature. All diagnostic report APIs are now listed as stable,
with the exception of report-on-fatalerror, which still has a
few bugs to work out.

PR-URL: https://github.com/nodejs/node/pull/32242
Fixes: https://github.com/nodejs/node/issues/26293


Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: David Carlier <devnexen@gmail.com>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>