Ingest Pipeline UI should allow to select the type of the field in the set processor

[philippkahr]

Description

When adding a set processor through the JSON:

POST _ingest/pipeline/_simulate
{
  "docs": [
    {
      "_source": {
        "time": "abc"
      }
    }
  ],
  "pipeline": {
    "processors": [
      {
        "set": {
          "field": "number",
          "value": 1
        }
      }
    ]
  }
}

We can specify it to be a number by not adding quotes around the value. This now means that I get back a numerical field. However in the inges tpipeline UI regardless of what I put into the text box it will always be serialized as a string, forcing me to add an additional convert processor afterwards.

[elasticmachine]

Pinging @elastic/kibana-management (Team:Kibana Management)