IncludeCollector is renamed to BuildDependencyCollector. It is now
returning a BuildDependency instead of individual getter. The test coverage
is improved too.
Task-number: QTCREATORBUG-21379
Change-Id: Ifc2d1c40c85772cf498c21968de526f4408b6023
Reviewed-by: Ivan Donchevskii <ivan.donchevskii@qt.io>