test(ui): failing bUnit tests for OpcUaEndpointEditor new sections
Adds 10 new tests covering:
- Authentication section label + Enable/Remove toggle (creates/nulls UserIdentity)
- TokenType conditional rendering: UsernamePassword shows Username/Password,
X509Certificate shows Certificate path/password, Anonymous shows no extras
- Deadband Enable/Remove toggle
- Advanced Subscription section labels (Discard oldest, Subscription display
name, Subscription priority, Timestamps to return)
- UserIdentity per-field error rendering under Username
9 new tests fail because the editor component hasn't been extended yet
(TDD red phase). Layer E2 implements the sections.