Add Zstd compression and improve compression configuration

[DRSchlaubi]

This PR has 2 goals:

• Add support for Zstd
• Add proper compression configuration

Currently there is no real way to disable compression, the un-documented way is to remove the compress parameter from the gateway url, this PR adds a compression property to the relevant builders

val kord = Kord(token) {
  compression = Compression.Zstd
}