Resolve "Deleting a link with a Delete press makes the app crash"
Closes #122 (closed) Seems that when deleting an edge the new 'useOnSelectionChange' does not have the chance to run as it does when deleting a node. The selectedElement is not then re-directed to the 'graph' and the sidebar crashes as there is no edgeData for the deleted edge. Added a check in the 'onEdgesChange' that runs first and detects the removal. A test was also added for deleting nodes and links using the keyboard.