Summary:
Log bytes before/after (de)compression to the logging backend. Use the codec name in the key, and for lz4/zstd also include the library version and compression level.

I chose the keys such that each individual piece as <= 15 characters, to be inlined. However, I chose readability of the keys over trying to squeeze the entire key in 15 characters.

Reviewed By: yfeldblum

Differential Revision: D6745720

fbshipit-source-id: 1249d203df610cb29c16e03f7a06ea90aea80418