feat: allow all config options when using connection string and object

[satire-foxfire]

I don't believe there is a way to do this currently, so I believe this would fall more into a feature request than a question, but let me know if there is a way to do this with the current functionality.

Currently you can use both a connection string while still specifying some options like ssl, but other options like user or password don't appear to get merged (they're ignored) unless they're explicitly part of the connection string.

Works:

const connectionString = 'postgres://user:password@hostname:port/database';
const client = new pg.Client({
  connectionString,
  ssl: true,
});

Doesn't work:

const connectionString = 'postgres://hostname:port/database';
const client = new pg.Client({
  connectionString,
  user: 'user',
  password: 'password',
  ssl: true,
});

The alternative I have right now is preparsing the connection string into an instance of URL first, then manually setting url.user = 'user' and url.password = 'password', and then stringifying it before passing it into the client:

const connectionString = 'postgres://hostname:port/database';
const url = new URL(connectionString);

url.user = 'user';
url.password = 'password';

const client = new pg.Client({
  connectionString: String(connectionString),
  ssl: true,
});

It'd be really nice for all the properties to "just work", while keeping the same behavior that anything defined in the connection string directly will take precedence.