RFC: Remove "Reduce resolution of preview image" option

[jenshannoschwalm]

From my understanding this option only makes sense on very slow machines but even then the performance gain will be subtle as full pipe will be the main burden. As time goes by machines got faster the last years ...

Preview pipe output

1. will be used by other modules for processing the full pipe leading to biggers errors/differences
2. is used by pickers. We have people complaining about pickers not being precise enough due to this, with further reduced resolution this gets even worse.

So, do we want this option?
a) make this option hidden in preferences as a hint like "don't touch unless you fully understand what you are doing"
b) remove that code from codebase
c) leave it as is

[victoryforce]

I vote for a), at least we can start with this and look at user feedback.