Provide `Device::is_{input/output}_format_supported`

[mitchmindtree]

There are a few problems with the current supported_formats method:

1. Many devices support massive numbers of supported formats and it is impractical to try and iterate over them all.
2. The alsa and wasapi backends are only able to provide supported_formats by querying the device with arbitrary formats.
3. SupportedFormat only supports "range"s of sample rates. Perhaps a way of querying whether or not Formats are supported is more useful? Perhaps the supported_{input/output}_formats methods could be changed to known_supported_input/output_formats to clarify that it only returns a subset of all supported stream formats?

[KillyMXI]

I really would like to be able to test wasapi devices for a particular format with a particular sample type.

Edit: although, specifically for wasapi, it will be useless anyway, due to the way Windows works with audio devices.

[Ralith]

I think replacing supported_*_formats with is_*_format_supported wholesale makes a lot of sense. The latter is strictly more general. I'd specifically prefer for there not to be an that returns a subset of some hardcoded list of common formats, but exposing very common formats as constants for user convenience, given that the user will still have to test for support, might still be nice.