Improve instrumentation for debugging of widget geometry :

umbrello/umlscene.cpp
- In function addWidgetCmd,
  - use DEBUG(DBG_SRC) in lieu of uDebug();
  - add printing of name, width, height.

umbrello/umlwidgets/classifierwidget.cpp
- In function calculateSize add DEBUG(DBG_SRC) message printing current
  and calculated width/height.

umbrello/umlwidgets/umlwidget.cpp
- In function constrain() case fixedAspectRatio() add DEBUG(DBG_SRC)
  message printing input and recalculated height.
- In function adjustAssocs replace qDebug() by DEBUG(DBG_SRC) and print
  name/width/height in lieu of `this' pointer.
- In functions setSize, updateGeometry add debug statement printing name
  and geometry related members.

umbrello/umlwidgets/widgetbase.cpp
- In function setRect replace uDebug() by DEBUG(DBG_SRC) and print
  `rect' in lieu of rect.x(), rect.y().

CCBUG: 447866