feat: extract component from AFX

[PRGfx]

When a range in AFX in selected, you can find the "Extract component" option in the refactoring menu.
This will open a dialog prompting you for a name for the new component and showing a preview of the generated output: the new component and the code generated at the old location.
You can currently choose whether to include the children in the component or not (only works when a "complete" tag is selected, i.e. no surrounding text or sibling elements). This will make the difference of generating <New /> vs <New>existing child content</New> and <Original>existing child content</Original> vs. <Original>{props.content}</Original>.

It tries to expose the "dynamic values" (not explicit variables, but everything in an eel expression) so it should still work in the end, but for now my confidence is limited ^^

The extracted prototype is created in the same file and I don't intend to make this configurable. That's what #323 is intended for.

This currently is super rough, but I decided to put it out there for feedback or interested testers.
Working with the injected language elements felt super awkward, but possibly I just haven't understood the intended way yet.

ToDo:

• add tests
• focus name input for faster editing
• add warning, if selected name is already known (could be in a different fusion tree, so I wouldn't add an error)
• make selection of AFX content more stable - currently it's super wonky when selecting anything outside of AST element bounds
• (make exposed props selectable from list)
• (make exposed props renamable)
• (toggle all advanced options in the dialog for easy every-day usage? second refactoring action for quick/advanced extract?)
• (try to derive better names for exposed props?)
• (try to derive a sensible default type?)
• (move carets to new positions)
• (make base-prototype configurable? We expect Neos.Fusion:Component behavior, but could be some subtype.)

Includes the EelElementFactory from #324 but deliberately not the whole branch.
Resolves #46

[PRGfx]

I started adding some tests, but I had more trouble with the prop refactoring than I'm willing to debug right now, so I close this in favor of a more minimal approach for the time being.