Returns a blob url from an http: or https: url


## Description

It takes 1 argument, a url to an asset online

`blob(url)`

- `url` is a string, starting with http:// or https://

## Usage

- `url('https://raw.githubusercontent.com/polygonjs/polygonjs-assets/master/textures/markertracking/marker_tracking1.png')` - return a url like blob:http://localhost:5000/af3f2f10-8de4-463e-9d83-82d24287f071