Evaluate using std::* smart pointers in Qt APIs

We want to investigate a possibility of using std::*smart pointers in Qt APIs.

There are at least two usage scenarios should be investigated:

• Use in header files (either inline functions or template classes)
• Use purely as implementation details (only in cpp files)
• Use in private APIs
• Use entirely instead of raw pointers (i.e. across library boundaries)

The following issues should be addressed for each of the cases listed above:

• Memory management (how do we allocate and de-allocate memory)
• Binary compatibility (what is guaranteed by different compilers/standard libraries vendors)

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

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

Note: creating subtasks for this user story is the right thing.

Some earlier discussions:

• unique_ptr and Qt
• unique_ptr and Qt, Take 2