Allow smooth drawing of memory and network graph to be disabled

I prefer the non smooth graphs, but they are currently only supported for cpu usage, so here a is merge request changing that.

A non smooth network graph: And here the expanded preferences menu:

If there is something i should do with the translation files, let me know, but with a bit of looking around in the internet i couldn't really find a on how to update them, and just manually editing them seems like the wrong way to handle that.

I am aware of !11 (closed), but it doesn't look like that is going to get merged any time soon.

Changes:

• Add options to disable smooth drawing of the memory and network graphs
• Reduce the rendering y offset to 3 to prevent non smooth cpu graphs to reach far enough up to no longer get fully rendered.