Add support more TLS cryptography libs

[Desiders]

Motivation

Currently, we hardcode sqlx?/tls-rustls on runtime-{}-rustls, but sqlx support many other features:

tls-rustls = ["tls-rustls-ring"] # For backwards compatibility
tls-rustls-aws-lc-rs = []
tls-rustls-ring = ["tls-rustls-ring-webpki"] # For backwards compatibility
tls-rustls-ring-webpki = []
tls-rustls-ring-native-roots = []

I think we should support at least aws-lc-rs, because it is now the standard crypto library.

Proposed Solutions

Add feature like runtime-{}-rustls-ring (default via runtime-{}-rustls) and runtime-{}-rustls-aws-lc-rs

Additional Information

This isn't so much about one library offering advantages over another, but rather the problem that the lack of customization can lead to conflicts across libraries when someone hardcodes a variant.