Allow results to be retained when merging Test Runs with differing Datasets

Background
Currently, when merging a Test Run that uses a Parameterized Test, the Actual Result field is erased if changes are made to the Dataset (e.g., renaming a parameter). This happens because, after modifying the Dataset, existing Test Runs must be reset, as it is unclear whether the changes affect the meaning of the steps.

Suggestions
Instead of automatically resetting the iteration and clearing the Actual Result field, users should have the ability to retain the actual result field.