(SActivitySequencer): qml import path is not properly defined

What does this MR do?

Check if a qml folder exist on the application root folder (for installed application) and use the conan path otherwise.

How to test it?

Package an application using ::uiActivitiesQt::editor::SActivitySequencer (ExActivities), install it on a non-dev computer without conan packages. The application should properly work.

Associated Issues/Merge Requests

• Issues
  • Fixes #426 (closed)