Add restart with debug level logging (PR #6721)
Fixes #6689
- An option has been added to the exit dialog to restart with debug level logging. This provides a convenience to users who wish to enable debug level logging temporarily (one run of nvda).
- A start up command line argument (`--debug-logging`) has been added to make it easier to start nvda with debug level logging.
Enabling debug logging in this way sets the log level earlier than setting it via the configuration file. In particular, this allows the debug messages that occur during the loading of the configuration file to be present in the log file.
