OSD wire-format fix (CreateOSD/SetOSD/GetOSDs/GetOSD all using the
wrong wrapper element names — strict cameras rejected the requests
and our parsers returned empty for non-empty responses).

API additions: OsdOptions.{date_formats, time_formats,
font_size_range}, NotificationMessage.property_operation, PartialEq
on OSD types, and SOAP request/response trace logging in
OnvifClient::call for diagnosing schema-validation faults.

Pure additive except the OSD fix — see CHANGELOG for the full
breakdown.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>