Trigger plotly_clickannotation when editable:true

[etpinard]

fixes #1750

before: https://codepen.io/etpinard/pen/JQWpZB?editors=1010
after: https://codepen.io/etpinard/pen/dBvdKw?editors=1010

cc @plotly/plotly_js and note that:

plotly.js/src/components/annotations/attributes.js

Lines 520 to 532 in 795220f

	captureevents: {
	valType: 'boolean',
	role: 'info',
	editType: 'arraydraw',
	description: [
	'Determines whether the annotation text box captures mouse move',
	'and click events, or allows those events to pass through to data',
	'points in the plot that may be behind the annotation. By default',
	'`captureevents` is *false* unless `hovertext` is provided.',
	'If you use the event `plotly_clickannotation` without `hovertext`',
	'you must explicitly enable `captureevents`.'
	].join(' ')
	},

[archmoj]

Nicely done.
💃