bug: Current key value is lost when dragged onto another key, in the Dopesheet.
expected result: Current key value should replace value of key on which the key was dragged.
This works as expected in the Curves view, should be the same behaviour in the Dopesheet.

repo:
-create two keys over time with different values.
-drag one key onto the other, in the Dopesheet vs. Curves view.
Curves view behaves as expected, Dopesheet loses current key value on override of existing key.