Potential memory leak in PointerVector pushBack, if internal vector reallocation fails.

[Dimi1010]

In large parts of the code base, PoiterVector::pushBack() is being used as pVector.pushBack(new T(...));. With the current pushBack implementation, if the internal call to m_vector.push_back() requires a reallocation and fails, the pointed element is leaked in those cases.

Opening an issue instead of directly addressing it in a PR, because there are a couple possible ways to address it:

• Assume ownership is transferred at the pushBack call and clean up the element on error.
• Provide a flag cleanupOnError to let the call site determine if the vector should handle the cleanup or the call site.
• Assume the call site will handle cleanup of the pointed element on exception and don't do anything in the vector itself.