feat: add cf context option for universal framework support

[imjlk]

Resolve #1

This PR adds a new cf option to CloudflarePluginOptions that allows users to provide their own Cloudflare geolocation context, enabling better integration with various frameworks like OpenNext, Hono, Sveltekit, and others.

I haven’t applied it with the Opennext example yet, but how about trying to do it this way? I made the changes minimally. Please take a look. Thanks!

[zpg6]

This is great! Can you add an example with Hono or one of the other frameworks?

[zpg6]

Hi @imjlk - this is working great so far. I tested with the opennextjs example (it is what's live on Demo Site)... also decided to make the geolocation type a bit more flexible.

Can you add an example with Hono or one of the other frameworks? Added already :)

[imjlk]

Wow, thank you! Haha, I was a bit lacking, but you wrapped it up quickly. I’ll try to submit a PR with a SvelteKit example next time. Thanks!