activateEditable method
Activate the specified editable, also deactivates all other editables.
Note this does NOT set the isActive flag on the editable itself, it just deactivates all other editables by setting the active flag to false then makes the editable supplied the activeEditable.
Implementation
void activateEditable(AlohaEditable editable) {
if (!_ready) throw AlohaException(AlohaException.notReady);
final editableProxy = editable.proxy;
_alohaContext.callMethod('activateEditable', [editableProxy]);
}