Support `rgb(R G B)` (without commas) as valid color format

Steps to reproduce:

  • Open this svg in Inkscape 1.3

  • Expect to see patterns rendered like..

    image

  • instead see...

    image

What should have happened?

  • would expect the pattern to show correctly.

Inkscape Version and Operating System:

  • Inkscape Version: 1.3
  • Operating System: Windows
  • Operating System version: 10