Rotate Polygon Labels

**Is your feature request related to a problem? Please describe.**
While we can move and scale a polygon label after drawing it, we can not rotate it. It would be useful when we need to annotate the same shape but in different orientations.

**Describe the solution you'd like**
A nice nice solution would be to add a rotating cursor when we move the label, in the same style as what do most of graphical tools, such as Word, Powerpoint, ..., (see below).

**Describe alternatives you've considered**
A nice alternative would be to add a shortcut to perform rotation clockwise and counter clockwise, but a rotating step should be defined, and would be less flexible than the above solution.

**Additional context**
Here is an example of the rotation indicator in Word :