buffer datatype support

[Pyseph]

With the release of Roblox's buffer datatype, which works with remotes, this module should add support for it also.

Benchmarking is required to figure out how the length is stored; my educated guess for now is that they likely use a VLQ size format, similar to strings and tables!

[Pyseph]

This has been rudimentally addressed as of v2.4.1](873c1b0), though it's not a complete fix. Most notably, Roblox compresses buffers past an unknown size limit. It has also not been extensively benchmarked; instead, I only made a bold assumption that it uses the exact same format as strings.

[metatablecat]

You can make an educated guess about the buffer size by passing through JSONEncode, which will give you the packet identical to the one used when sending it over a remote.

I found this by accident when I was testing a memory crash issue that's no longer active. Also don't we have a way to explicitly get a compressed size now?