androiddeployqt: qmlimportscanner support

Enables qmlimportscanner support in the deployment tool. Will
use the root path set by qmake to determine dependencies, which
by default will be the location of the project's .pro file.

Other effects: This removes the requirement to add QT += foobar
to enable using imports from the module QtFooBar, and it also
enables adding custom QML imports.

[ChangeLog][Android][androiddeployqt] Added support for using
qmlimportscanner to detect QML import dependencies of application.

Task-number: QTBUG-34175
Change-Id: I5af5964f9e453121eeff8b442f0c5e72676b1fbe
Reviewed-by: BogDan Vatra <bogdan@kde.org>