feat: use Astro's built-in pagination

[DerTimonius]

Description

This PR implements the built-in pagination of Astro instead of the current self-made. Don't get me wrong, the self-made pagination is great, but I found that sometimes it might be hard to find the correct file in the pages directory that causes an issue.

The upside is that getting the next and previous urls is much easier and does not need manual string concatenation.

I also removed the files with the helper functions that facilitated the previous pagination.

Closes #370

[satnaing]

I found some issues.
I got the following error when I build the project.

`Astro.request.headers` is unavailable in "static" output mode, and in prerendered pages within "hybrid" and "server" output modes. If you need access to request headers, make sure that `output` is configured as either `"server"` or `output: "hybrid"` in your config file, and that the page accessing the headers is rendered on-demand.

There are some questions while solving the above issue

• Is it possible to make the warning disappear without making "server" or "hybrid" output?
• Is there any other way to deal with this without making any redirects?

---

Another thing is that the type of page is being Page<any>.
We can make the type a bit more strict.

I can co-author this if you don't want to do TS related stuff. Or you can do it yourself if you want. I don't mind either way 🤷

[satnaing]

Turns out both can be solved easily.

[satnaing]

Hell @DerTimonius,
Do you want to update yourself?
If you need my help, plz do let me know.

[DerTimonius]

@satnaing sorry, a lot of work today. I can update this myself, probably tomorrow afternoon, or on the weekend. I'll try to tackle the typescript shenanigans myself 😄

[DerTimonius]

Is this the approach you had im mind, @satnaing?

[satnaing]

LGTM
Thanks for your contribution.