Add settings option to always ask for file type

[MateuszGrabuszynski]

Is your feature request related to a problem? Please describe.
I sometimes have the files with *.yuv name, which are actually RGB. I know that's not necessarily the right way.

Describe the solution you'd like
It would be beneficial, if there was an option in settings to ask for the format for each opened file, even if the filename suggests it.

Describe alternatives you've considered
It does prompt for format, when the names of the files are changed, e.g. to *.bin.

[ChristianFeldmann]

Definitely a very edgy edge case but might be useful for other people as well. Will take a look ...

[ChristianFeldmann]

That was a smaller refactor so I added it:

Enjoy!