adjust hyara to work in BN plugin manager, PySide 6 support

[psifertex]

Only thing left is to create the tag and release (I've already updated the version in the readme and the new plugin.json required for the plugin manager. This PR:

• Adds PySide6 support for BN 3.0 and newer (which uses Qt6 and PySide6)
• Update readme to work better in the plugin manager view (there's still a few visual quirks I might fix later but this is good enough for now). Looks visually identical in the GH viewer from what I can tell.
• Change __init__.py to not auto-load cutter if cutter is not available.
• Added new plugin.json file for BN plugin manager. Feel free to change anything in there, works pretty well though so far!
• Mostly just moved a few files around and changed imports accordingly

Oh, if you happen to ever remake the introduction GIF it would be great if it started on BN first because our plugin manager doesn't support animated gifs and it's a bit awkward that the first frame shows IDA. 🤣 Of course, Lighthouse has the same issue.

Once you accept the PR and create the release, I'll add it to the official plugin manager and it will look like this for everyone!

A few other long-term notes while I'm at it:

• There's a newer more reliable method to get the current bv instead of the DockWidget method, I'll try to remember to PR that later.
• In the future, dock-widgets will be deprecated and should eventually be replaced with global area, panel, or view widgets, but that is also a more substantial change for another time.

This PR resolves #9.