Add an input gesture to perform secondary UIA actions

[pitermach]

Is your feature request related to a problem? Please describe.

I'm working with an application that currently has no keyboard support and has to be used exclusively with object navigation. Both Narrator and JAWS have commands to programmatically adjust sliders. NVDA only has 1 gesture, to perform the primary action. As a result, NVDA can only adjust sliders in 1 direction in this application.

Describe the solution you'd like

Having a gesture to perform secondary action on the navigator object (could be mapped to NVDA+Shift+Enter by default) would come in very useful here. It would also bring NVDA in line with other screen readers in regard to this feature.

Describe alternatives you've considered

I'm talking to the developer of this application to make the sliders keyboard accessible, but it may be some time before this happens and I suspect this issue will come up again with other applications written using this specific UI toolkit, so it'd be good to have a way of dealing with them without switching screen readers.

Additional context

The issue came up here:
surge-synthesizer/surge#4616