Add pg-native to monorepo

[brianc]

Makes fixing things like #3214 easier and generally makes contributing a bit easier. I didn't do much to "modernize" the pg-native codebase other than running it through the standard eslint --fix that is applied to the rest of the code. There's some easy opportunities there to update it to es6 and so on...it still uses some pretty antiquated coding styles in places.

[cloudflare-workers-and-pages]

Deploying node-postgres with    Cloudflare Pages

Latest commit:	e1514a3
Status:	✅  Deploy successful!
Preview URL:	https://878262f4.node-postgres.pages.dev
Branch Preview URL:	https://bmc-add-pg-native.node-postgres.pages.dev

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[brianc]

Took me a bit to fiddle w/ the cloudflare stuff I didn't write (but now I maintain, i suppose!) - that wrangler package was doing some at-runtime npx stuff, so I upgraded it. Anyways...also re-enabled native tests for node 20, and added node 22 to the test matrix - so libpq is building & working on all nodes again. yay. Will publish this in the am (so I can be around in case there's some weird regression introduced)