Move settings to Privacy and Security category (#19296)
Resolves #16272
### Summary of the issue:
NVDA has several settings that have a direct impact on users' privacy
and security, but they are scattered throughout its settings dialog.
### Description of user facing changes:
Some of these settings have now been moved to the Privacy and Security
category.
### Description of developer facing changes:
A few items have been removed from the public API.
### Description of development approach:
- Move the code for the logging level setting from
`GeneralSettingsPanel` to `PrivacyAndSecuritySettingsPanel`, and
slightly refactored it.
- Moved the code for the allow usage stats setting from
`GeneralSettingsPanel` to `PrivacyAndSecurityPanel`, and refactored
slightly.
- Searched the User Guide for references to logs/logging and
stats/statistics, and updated as appropriate.
### Testing strategy:
Tried changing log levels and ensured that the changes were reflected in
the log output and in the GUI.
Disabled the source check in `updateCheck`, and tried checking for an
update with usage stats gathering on and off, and checked that the
setting was reflected in the URL.
### Known issues with pull request:
Users may find it difficult to adjust to the change in location
