Trino Python client is broken if lz4/zstd native libs can't be loaded instead of degrading gracefully

[xkrogen]

After #509, dependencies were added on lz4/zstd, which have dependencies on platform-specific native libraries. Usually Python packaging will handle this transparently, but in some environments it may be challenging to get the native libs configured correctly and it generally makes the Trino client less portable. These encoding libraries are only required when the spooling protocol is used, and even if the spooling protocol is used, clients can choose which encoding to use, including json which does not require any native libs.

I propose that we make it so that if the imports for lz4/zstd fail, indicating an environment issue, we don't fail loading of the entire Trino library. Instead, it should just be impossible to use the json+lz4/json+zstd encodings for the spooled protocol, while leaving all other functionality intact.

[xkrogen]

@wendigo @hashhar @mdesmet I'm happy to work on this but wanted to get opinions before I start

[wendigo]

@xkrogen makes sense, client protocol works in a way that makes it possible to announce which encodings are supported an in that case we should announce only json if we can't load lz4/zstd