umbrello/petaltree2uml.cpp various fixes following commit 9bfc122d :

- In function fetchLocation,
  - revert change to argument of location.split();
  - do not adjust returned values by factor Rose2Qt when width or
    height are provided as 0.
- In function fetchDouble,
  - replace argument defaultValue by bool applyRose2Qt defaulting to
    true;
  - add debug statements on cases where 0.0 is returned;
  - adjust returned value by factor Rose2Qt only if applyRose2Qt is
    true.
- In function umbrellify case (dt != Uml::DiagramType::Undefined) for-
  loop, fix bug in handling of line_color and fill_color:
  The hexadecimal number provided to QColor constructor must be 6 hex
  digits wide. If less than 6 digits pad with leading zeros.

CCBUG: 81364