Evaluate using Qt smart pointers in Qt APIs

We want to investigate a possibility of using Qt pointers in Qt APIs.

There are no issues with memory management, binary compatibility and consistency. But we want to confirm it in scope of this user story.

The things to research:

• Check if there are any problems with memory management, binary compatibility and consistency
• Can more appropriate smart pointers (Scoped/Shared/Weak) be used "as-is"
• What should be improved in the smart pointers implementation

Acceptance criteria:
Research report(s) should be provided. The report should contain:

• Research subject
• Research method (s)
• Pros and cons
• Recommendations (optional)
• Conclusion

The report is here (available on for The Qt Company for now).