Custom media library for remote

[kwonoj]

This is partially overlapping to #46, however I'm not sure if it can be considered as identical so created a new issue. Please feel free to close if it isn't worth.

My motivation is quite similar to the original issue, basically allow to manage image assets to separate remote services where possible. The difference is, I'm curious if it can be a generic approach other than specific service.

One way I thought is creating a custom image field that uploads an image to remote service then returns a url to it, however I realized pagecms's media library won't be able to access those if that's the case.

So in summary q,

1. Would it be viable a user create their own custom fields to upload images into remote services?
2. If that's the case, is is possible to hook / customize pagecms's media library to work with those remote assets?

[hunvreus]

For now, I only manage media that is hosted on GitHub.

But with the Next.js version (#53), I'll have a better foundation to add more advanced features.

This includes 3rd party storage solutions like Amazon S3, Cloudflare R2 or Cloudinary (and probably others). I also want to allow for multiple media libraries, so you should be able to have some assets on S3 and others directly in GitHub.