publish ecosystem databases separately

[viceice]

We should publish the ecosystem db files as separate downloads. then we could fetch newer db when needed and not always download all files (the zip is currently ~40M)

[viceice]

We can also use a different compression then by simply using node built-ins. (eg brotli, zstd, ...)

[Churro]

Probably it makes sense to first do #1269, otherwise every download of a db would count towards the GH rate limit.