Creates an URL to a blob. This blob imports a script for use in a web worker (using `importScripts`).

@param {string} url The URL to the script that has to be loaded.
@returns {string} the URL to the blob.
function createBlobURL( url ) {
	const URL = window.URL || window.webkitURL;
	const BlobBuilder = window.BlobBuilder || window.WebKitBlobBuilder || window.MozBlobBuilder;

	let blob;
	try {
		blob = new Blob( [ "importScripts('" + url + "');" ], { type: "application/javascript" } );
	} catch ( e1 ) {
		const blobBuilder = new BlobBuilder();
		blobBuilder.append( "importScripts('" + url + "');" );
		blob = blobBuilder.getBlob( "application/javascript" );
	}
	return URL.createObjectURL( blob );
}