Handle user_ticket_login
Legacy Bambu network plugins completed embedded login with
user_login, which the WebView dialog already handled.
Newer Bambu login flows can complete with user_ticket_login and
return only a short-lived ticket. The external browser path already
worked because the local HTTP callback server exchanges that ticket
for tokens, fetches the user profile, and passes the resulting session
payload to change_user.
Mirror that ticket exchange path for embedded WebView login so the
dialog can handle user_ticket_login instead of silently ignoring it
after verification-code submission.
* Add get_json_string_field helper
Introduce get_json_string_field in OrcaCloudServiceAgent.cpp to safely extract string fields from JSON objects.
* Add resolve_display_name helper
Introduce resolve_display_name to normalize provider metadata labels for the UI. The helper returns the first non-empty value from display_name, nickname, full_name, name, falling back to username, resolving human-facing label across varying provider payloads.
* Replace safe_str anonymous function
Replace get_json_string_field for better readability.
* Replace resolution flow for nickname with function
Consolidate both flows into one function for easier maintenance and more consistency.
* Update OrcaCloudServiceAgent.hpp
* Add OrcaCloudServiceAgent display name tests
Add unit tests verifying OrcaCloudServiceAgent resolves a user's display name from various session JSON shapes.
Andrew