feat: add basic kitty protocol support

[NSPC911]

i forgot to pr this, but you can close this if you prefer only tgp to exist

[lnqs]

Could you explain what this PR is for? It's a second TGP implementation, isn't it?

[NSPC911]

Well yes, but not all terminals support TGP. Most support the basic Kitty Image implementation, but not TGP.

It would make sense to remove TGP and have just Kitty because Kitty has more terminals supported as compared to TGP, but it is up to you.

[lnqs]

The protocol Kitty uses to render images is called Terminal Graphics Protocol, regardless of using the unicode placeholders or not.
However, as TGP is the only protocol that works without major glitches due to the placeholders I don't think we should remove them. And maintaining a buggy and a more or less bug-free implementation of the same protocol doesn't seem right to me -- especially as won't be able to differentiate what terminals supports the placeholders.
I rather ask the terminal maintainers to implement the full spec instead of only parts of it.
Or, at some point, create some PRs against textual itself to make the hacks unnecessary this package implements that cause the issues and switch to TGP without placeholders then.

[NSPC911]

I really hope Textual does something to make image support official, the hacks needed for image support are just insane.

I will be leaving this PR in case you have second thoughts.