Support files greater than 4GB

[GWBasic]

Currently, files that are long are truncated. (See GWBasic/soft_matrix#77 )

I've determined this is because RIFF + WAV has limitations imposed by 32-bit lengths specified in the file.

Specifically, https://docs.fileformat.com/audio/wav/ states that bytes 5-8 are the length of the file, in bytes. A 32-bit 6-channel wav that's 2 hours will be 8GB. This overflows RIFF's file length field.

In this bug: Figure out how to construct wav files that are longer than 32-bit RIFF file limits. https://www.loc.gov/preservation/digital/formats/fdd/fdd000001.shtml#notes might explain how to do this.

Note: Wave files > 4GB in length will not be supported. The reason is that there are two competing proposals to alter the wave file format, and support for these file formats in other applications is very limited. A much better approach for files > 4GB is to use an alternate file format, like AIFF.

I currently do not intend on supporting other audio file formats in wave_stream. At some point it may make sense to write a sister library called "aiff_stream," and possibly a library that allows reading and writing both.

[GWBasic]

It looks like there are two approaches to long wave files, described at: https://gearspace.com/board/music-computers/1086321-do-you-use-rf64.html

In general, there's Wave64 and RF64. Both appear to have inconsistent support.

For the moment, I'm not going to support these.

[GWBasic]

At the point, the appropriate "fix" is to return an error whenever anyone attempts to write a file larger than 4GB.