Transparent compression of database

[powellnorma]

With https://github.com/phiresky/sqlite-zstd we could select columns (e.g. events.data) that will get compressed on the fly. I think it would make sense to add this (perhaps as opt-in), what do you think?

[ErikBjare]

I think I've seen that before, or something similar, but it looks quite good!

I'd be open to merging it under a feature flag, and then make it the default if it performs well.