Clap detection

[microbit-carlos]

CODAL has added a "clap" event, similar to "loud" and "quiet".

• lancaster-university/codal-core@99b9399
• docs: Add SoundEvent.CLAP. bbcmicrobit/micropython#793

[microbit-carlos]

For the set_threshold() method we'll need to throw an exception if the "clap" event is provided, as that threshold cannot be configured.

[dpgeorge]

SoundEvent.CLAP is added in 8b8c1d3

For the set_threshold() method we'll need to throw an exception if the "clap" event is provided,

This is also done (didn't need any changes, was already raising an exception for invalid sound events).

[dpgeorge]

@microbit-carlos this is already done (see above). I tested it and it seems to work, microphone.get_events() does emit a SoundEvent.CLAP on occasion.