Support for multivalue patching

[SebastiaanKloos]

Microsoft SCIM validator uses multivalue replace operations. This PR adds support for that.

{
  "schemas": [
    "urn:ietf:params:scim:api:messages:2.0:PatchOp"
  ],
  "Operations": [
    {
      "op": "replace",
      "value": {
        "active": true,
        "name.givenName": "Hello world!"
      }
    }
  ]
}

[arietimmerman]

Thanks for your pull request. I'll dive into the specs regarding this, but think this not only applies to replace but also to add and remove.

[arietimmerman]

Based on your input, I have implemented it in a different way, which I believe provides more flexibility. See #89

[SebastiaanKloos]

Thank you 😃