feat: oEmbed implementation

[KararTY]

Pull request checklist:

• CHANGELOG.md was updated, if applicable

Description

Old stuff

Unfinished, I feel like this needs more thought put into it.
Should we do it this way?
Should we handle each oEmbed separately maybe?

Lacking:
Custom resolvers for some services like Instagram (Needs a token).
Some services are not in the providers file, instead they offer a "discovery" url in their HTML document metafields, this has to be implemented somehow.

Features:

• Resolves custom oEmbeds based on resolvers.json file.
• Support for Instagram & Facebook oEmbed service (Thanks @pajlada)

Full original providers file (Chatterino/api comes with its own modified file):
https://oembed.com/providers.json

[leon-richardt]

Quick overview: https://oembed.com/

[pajlada]

Looks good to me 👍

[KararTY]

Looks good to me 👍

For future reference's sake:
Some oEmbed providers don't provide a lot of information in oEmbed, but provide OpenGraph fields and so here's another idea that could potentially be spun into its own PR/Issue:

we could also combine OG and oE date with a clever model - @leon-richardt

[pajlada]

LGTM 👍

[zneix]

I guess it's all fine unless I've missed something.