Allow SSL parameters to be passed directly

Right now certain SSL parameters like sslcert, sslidentity etc require you to pass a file path. This is not ideal in many places you can read these parameters from the environment.

So we need to allow people to pass them directly to the connection string.

[pantharshit00]

I am really not sure but main use case here is on some serverless services, you can’t really can’t have the p12 file and you will need to read it from secret: https://github.com/vercel/vercel/issues/749#issuecomment-533873759. Issue on our repository about it: https://github.com/prisma/prisma/issues/1673

In most libraries you can read from the environment and pass it. So for example in this Rust crate: https://docs.rs/postgres-native-tls/0.3.0/postgres_native_tls/ which I believe we use in quaint you can just call std::env and pass the certificate.

So we need a way to pass the certificate as string.

[danaugrs]

@callumlocke I actually used this exact approach on Vercel to deploy Umami (https://github.com/mikecao/umami/issues/880) last year. I based my solution on https://github.com/prisma/prisma/issues/1673#issuecomment-647107891.

However, I recently tried redeploying Umami on Vercel and did not need to do anything special.