Add support for the sslnegotiation DSN option

[analytically]

No description provided.

[analytically]

Hi @taylorsilva, please review, this adds support for the sslnegotiation parameter. A new parameter in Postgres 17 allows for direct TLS handshakes, reducing network latency and improving the performance of secure connections​.

[taylorsilva]

This looks good, the tests pass. Only thing I'm not sure about is if this requires lib/pq to support this feature? I don't know enough about what limits the driver places on us in regards to version specific features like this.

Seeing issues like this one in the lib/pq project makes me think this won't do anything 🙁
lib/pq#1175

[taylorsilva]

Yeah looking at https://github.com/lib/pq/blob/master/ssl.go
I think the driver needs to be updated. But based on the project's README it doesn't look like they'll be adding this feature any time soon. Someone smarter than me let me know if I'm reading this all wrong though 🙏

[conradludgate]

Adding this feature to lib/pq should just be a case of adding an if statement around https://github.com/lib/pq/blob/3d613208bca2e74f2a20e04126ed30bcb5c4cc27/conn.go#L1116-L1130. Indeed a question whether the maintainers will respond to such a patch, however. I'll open one