[ML] Anomaly explorer swimlane limit control resets on job change

[peteharverson]

If the 'limit' control of the Anomaly Explorer 'view by' swimlane has been changed from the default setting of 10, on changing the job selection in the view, the swimlane is re-rendered for the new job selection with the number of lanes equal to the previous 'limit' setting, but the selection on the control is reset back to 10 :

On changing jobs, the number of lanes, and the selection on the control, should both be retained.

[elasticmachine]

Pinging @elastic/ml-ui (:ml)