Coin should be used to build everything we need in addition Qt5 and single-module products.
This means that Coin needs to be able to handle product level dependencies where other product can have submodules too.

For example:

• automotive (includes multiple submodules) -> qt5
• automation -> qt5
• qtcreator (contains submodules/plugins) -> qt5

This is needed in order to migrate the rest of the builds from Jenkins based system to Coin.

This also enables other products to follow their release schedules more independently from qt5 schedules. Each
product can be pinned to wanted ref of Qt5 (sha1, tag, branch head). Currently all automation and automotive submodules are part
of tqtc-qt5.git which brings it's own challenges.

In addition to this it would be useful to be able to declare and build more complex product dependencies later on:

• qtsdk.git
  • Qt5 (v5.12.0)
  • QtCreator (4.5) -> Qt5 (v5.12.0)
  • ProductFoo (1.0) -> Qt5 (v5.10.0)
  • ProductBar (2.0) -> Qt5 (vX.X.X)
                                     -> A (v.X.X.X) -> Qt5 (v.X.X.X)
  • Automotive -> ...
  • Automation -> ...