feat: iterm2 inline image protocol support

[NSPC911]

very very questionable, still very much wip, mostly just a proof of concept, but still has the same issues as sixel, if not more (#86 also occurs)

resolves #68

[lnqs]

Hey, sorry for the late response. I'd be happy to merge iterm2 support, but I also can't test it as I don't have access to a mac.
After reading through code it looks fine to me, even though it could probably make sense to refactor some of the functionality shared between Sixel and iTerm2 to a common place.

[NSPC911]

I don't think you need a Mac to test this, this works on Wezterm because it has iTerm2 Inline Image Protocol, along with Rio Terminal (albeit in a less stable form)

However, I'm not able to fix issues related to Textual not properly rewriting the borders on the bottom, leading to issues quite similar to Sixel, or even worse.

[lnqs]

I guess the basic problem is how textual-image works. It's basically bunch of hacks hooking into textual functionality to inject data. To have a cleaner and more reliable implementation, changes to textual itself would be needed.

[NSPC911]

I was trying to vibe-code a chafa implementation NSPC911/textual-chafa, but it feels quite iffy because certain terminals just don't show anything (rio supports iT2 and sixel, but chafa displays nothing). I think it solved the border issues there, but I'll need to take a closer look as to what it actually did

However, I don't think I will be making this PR ready. Feel free to continue from my checkpoint. I may attempt to add enhanced Sixel support soon, but only time will tell.