docs: add comprehensive NotificationLogSettings documentation

- Add detailed NotificationLogSettings configuration documentation to environment-configuration-settings.rst
- Include all 9 configuration options: EnableConsole, ConsoleLevel, ConsoleJson, EnableColor, EnableFile, FileLevel, FileJson, FileLocation, AdvancedLoggingJSON
- Add cross-reference in main logging documentation
- Address customer issue with "no advanced logging configuration for notifications" debug messages
- Follow same documentation structure and format as existing LogSettings

Resolves #8075

Co-authored-by: Carrie Warner (Mattermost) <cwarnermm@users.noreply.github.com>

Author: claude[bot]