webui2: about page, fix format

Signed-off-by: Richard Marko <rmarko@fedoraproject.org>
storage: remove ReprotBacktrace.btp_thread()

Signed-off-by: Richard Marko <rmarko@fedoraproject.org>
webui2: add json responses for reports & problems

Signed-off-by: Richard Marko <rmarko@fedoraproject.org>