Allow setting cancelAll() options on {{cancel-all}} helper

[nwhittaker]

An enhancement request to add support to the {{cancel-all}} helper for passing options through to the task's cancelAll() method.

Observed

Currently the helper only passes on the task and sets a hard-coded reason:

ember-concurrency/addon/helpers/cancel-all.js

Lines 16 to 19 in 90cca1e

	return taskHelperClosure('cancel-all', 'cancelAll', [
	cancelable,
	{ reason: CANCEL_REASON },
	]);

Expected

The helper has optional args for setting the cancelAll options:

{{cancel-all this.task reason='…' resetState=true}}