Add support for continuous listening

[RoboEvangelist]

Instead of pressing a key, continuously listen till the wake work is announced (i.e., "Hey Ross")

[mhubii]

great suggestion! Happy to review a PR @RoboEvangelist .

Currently, you can use the max_duration in the action message

ros2_whisper/whisper_msgs/action/Inference.action

Line 5 in e512080

builtin_interfaces/Duration max_duration

to specify a duration.

Any idea how this could be handled better?

There are models for voice activity detection: https://github.com/snakers4/silero-vad

Once activity is detected, the action server could be called.