Add a newAclForResource() helper method

[dmitrizagidulin]

Currently, in order to create a new ACL resource, one has to do something like:

let url = 'https://example.com/resource1'
solid.web.options(url)
  .then(response => {
    let aclUrl = response.aclAbsoluteUrl()
    let ps = new PermissionSet(url, aclUrl, response.isContainer(), { rdf, webClient })
    // .. set up permissions here
    return ps.save()
  })

A helper method would make this process easier. So, instead:

let url = 'https://example.com/resource1'
solid.newAclForResource(url)
  .then(permissionSet => {
     // set up permissions
     return permissionSet.save()
  })