report: Strengthen report_csp_violations type using WildValue.
report: Strengthen report_csp_violations type using WildValue.

Signed-off-by: Anders Kaseorg <dfdb7392591db597bc41cf266a9c3bc12a2706e5@zulip.com>

rht/zulip,zulip/zulip,andersk/zulip,rht/zulip,kou/zulip,rht/zulip,rht/zulip,kou/zulip,andersk/zulip,andersk/zulip,zulip/zulip,andersk/zulip,kou/zulip,kou/zulip,andersk/zulip,zulip/zulip,zulip/zulip,andersk/zulip,rht/zulip,andersk/zulip,kou/zulip,zulip/zulip,zulip/zulip,rht/zulip,kou/zulip,rht/zulip,zulip/zulip,kou/zulip