Add unassigned command to show Remote Access settings (#18006)
Closes #17962
Summary of the issue:
There is no way to open Remote Access' settings directly.
Description of user facing changes
There is now an unassigned command to open Remote Access's settings.
Description of development approach
Added a function to open Remote Access's settings to gui.MainFrame, and added an unbound script that calls that function in globalCommands.GlobalCommands. Modelled off other "Shows NVDA's settings" scripts.
