When is the next generation of photo fixing ?

At just 8MP, 4K is actually rather low resolution.  Any phone can take higher resolution images than that!  Of course, video is a whole other beast.  If you are talking only about video, then 6K and 8K cameras are already available.

Upping the resolution to, say, 8MP to 12MP is already a thing.  There are already several apps for computer that can increase the resolution of an image so that it can be printed with photo quality.  This is NOT to say that you can take a pixelated image of a license plate and make it clear; that's still Hollywood tomfoolery.

4k is considered low resolution for photography. As mentioned, you can't create a high resolution image from a low resolution image. If the information isn't there, you can't make it magically appear. The inverse correlation filters help, but leave lots of artifacts behind. Although, inverse correlators work pretty good for astronomy since you have point sources as references.

Resolution is limited by atmospherics. Ground-based astronomical telescopes have reduced atmospheric issues quite a bit by using adaptive optics.

Identifying materials has been done. Various techniques are in play currently. We have a hand-held unit at work that can determine metal composition that uses LIBS. I have worked on material analyzers using a 10MW pulsed laser for exotic materials 15 years ago and a mass spectrometer for geologic samples back in the mid 1980s.

Never.  'Photo fixing like from low resolution to 4k' is never going to happen as you can't add details to something that isn't there.  You CAN, however, enlarge photographs already using various bits of sotware ... BenVista PhotoZoom readily springs to mind ... and this uses various forms of interpolation in an attempt to 'fill in the missing details'.

'Zoomig in with good resolution 4k' already exists if you consider telescopes, but these would cost you millions of dollars.

'Revealing what's behind someone' couldn't possibly exist, though some softwares do allow you to 'remove' someone from a photograph and 'fill in details' based on surrounding pixels.

To see fingerprints on walls the wall would need to be perfectly smooth. i.e. covered in gloss paint for a 100% accurate identification of a fingerprint.

I'm not sure what you mean by "identify material".  What type of material are you referring to?  Scientists can already identify what makes certain types of material by using a technique called mass spectrum photometry.  I was using this in a laboratory more than 45 years ago.