The prop 'action' of EditControl cannot be updated when certain draw:* events happen, because of wrong event names

[edwardgaoyb]

Issue: The 'action' prop of EditControl cannot be triggered by some events, e.g. "draw:editStart"

Root cause: the event names here https://github.com/emilhe/dash-leaflet/blob/master/src/ts/components/EditControl.tsx#L64 seem to be inconsistent with react-leaflet-draw(https://github.com/alex3165/react-leaflet-draw/blob/master/src/EditControl.js). The event names are all lower case.