Timeline: Make label parsing declarative
Timeline: Make label parsing declarative

Like this the labels are also updated initially and when the model
changes. Also, use the more generic label "[unknown]" instead of
"<bytecode>" to replace empty descriptions. Even in the QML case it's
not always bytecode.

Change-Id: Iea0dc36eb9061c928f2cb9706adaaa3b4bab7811
Reviewed-by: Joerg Bornemann <47777b9406dbddd02a3fdca8341789a013805a11@theqtcompany.com>

kuba1/qtcreator,kuba1/qtcreator,danimo/qt-creator,martyone/sailfish-qtcreator,Distrotech/qtcreator,martyone/sailfish-qtcreator,xianian/qt-creator,xianian/qt-creator,martyone/sailfish-qtcreator,kuba1/qtcreator,kuba1/qtcreator,Distrotech/qtcreator,xianian/qt-creator,kuba1/qtcreator,danimo/qt-creator,kuba1/qtcreator,danimo/qt-creator,danimo/qt-creator,Distrotech/qtcreator,Distrotech/qtcreator,kuba1/qtcreator,martyone/sailfish-qtcreator,xianian/qt-creator,danimo/qt-creator,danimo/qt-creator,Distrotech/qtcreator,danimo/qt-creator,kuba1/qtcreator,danimo/qt-creator,xianian/qt-creator,danimo/qt-creator,xianian/qt-creator,kuba1/qtcreator,xianian/qt-creator,martyone/sailfish-qtcreator,martyone/sailfish-qtcreator,martyone/sailfish-qtcreator,martyone/sailfish-qtcreator,Distrotech/qtcreator,xianian/qt-creator,martyone/sailfish-qtcreator,xianian/qt-creator,Distrotech/qtcreator