Regarding building QML modules

[Aleix Pol]

Hi,
I received this bug report [1], I guess this should be figured out. It
suggests using add_library(MODULE) instead of add_library(SHARED) for
QML modules, as they are not meant to be linked to.

I think it makes sense, I would have done it like that since the
beginning if it wasn't because Qt requires a lib* prefix to the QML
plugins (only on linux?).

Any feedback will be welcome. Thanks!!

Aleix

[1] https://bugs.kde.org/show_bug.cgi?id=343449