Adds rotate path operation

[gquito]

45 #36

Here's an example of rotation of about the center of this sword by 90° .

[kuubeu]

Nice! A couple of notes from me:

• I think using something like "Origin X/Y" instead of "Rotate X/Y" and "Angle" instead of "Degree" in the input fields would be easier to understand (maybe the degree symbol (°) would append to the input?)
• If we changed the grid from 6fr 6fr 7fr to 1fr 1fr 1fr you could use 2fr 2fr 2fr 3fr instead, leaving a bit more space for the input fields:
• It would be nice if horizontal and vertical lines were kept or converted to the appropriate ones when rotating by multiples of 90°, instead of always being converted to lines

[Yqnn]

Thanks a lot @gquito for this very nice change 👍 I agree with the 3 remarks from @kuubeu, could you please fix at least the 2 first ones (label change + layout) ? Then I will merge the PR.