[feature request] Halt the recording after silence happens for a while

[josuah]

This will permit to avoid waiting that silence gets recorded after the query.

Currently, the duration of the recording is 6 seconds. Having another action (an extra touch, detecting silence...) can be used to terminate the recording: https://github.com/brilliantlabsAR/noa-for-ios/blob/main/ios/Noa/Noa/Monocle%20Assets/Scripts/audio.py#L7

(requested by email)