Adjustable Wavefile playback rate

[todbot]

This adds support for adjustable playback speed / rate to audiocore.Wavefile,
addressing issue #10881.

Tested on the following platforms: RP2040, SAMD21, SAMD51. Specifically:

Device	Size change	Percent used change
raspberry_pi_pico RP2040	925256 to 925856	88.59% to 88.64%
qtpy_m0_haxpress SAMD21	251760 to 252280	99.24% to 99.44%
pygamer SAMD51	491932 to 492380	98.44% to 98.53%

(numbers are for en_us build)

[todbot]

A bunch of the builds failed for weird non-PR reasons. ( Error: The process '/usr/bin/git' failed with exit code 128 in the "Set up repository" step)
Is this my fault? I don't think so. Seems like github in general is having issues.

[tannewt]

Is this my fault? I don't think so. Seems like github in general is having issues.

I doubt it. We can rerun when we're closer. I replied on the issue (#10881) about approach.