Wish import bitmap pdf

WIP is importing vector based pdfs nicely.
As we also often get bitmap based pdfs - scanned architectural plans with remarks etc - it would be great if we could import these as pictures. For now we have to extract the bitmaps in a separate tool, or have to make a sreenshot, save the picture and import it as pictureframe. One could also add a tool to vectorize bitmaps as in incscape, if that might be useful for some people - we can do without.

Hi Joerg - added to the pile, thanks.
https://mcneel.myjetbrains.com/youtrack/issue/RH-41682
-Pascal