Improve usability around recently unmapped and non-indexed fields

[inqueue]

Describe the feature:
A field that has been recently unmapped and/or not indexed which is still part of an index pattern can make applying index filtering a bit confusing for an end user, especially if the field is still exists in source. Applying a filter to a field only existing in source will of course result in 0 documents and will cause a query_shard_exception. An end user without intimate knowledge of the index or mapping may not know the reason.

Example

DELETE /data-test-*

PUT /data-test-1
{
  "mappings": {
    "dynamic": false,
    "properties": {
      "field_1": {
        "type": "keyword"
      },
      "field_2": {
        "type": "keyword"
      }
    }
  }
}

PUT /data-test-2
{
  "mappings": {
    "dynamic": false,
    "properties": {
      "field_1": {
        "type": "keyword"
      },
      "field_2": {
        "type": "keyword",
        "index": false. 
      }
    }
  }
}

PUT /data-test-3
{
  "mappings": {
    "dynamic": false,
    "properties": {
      "field_1": {
        "type": "keyword"
      }
    }
  }
}

POST /data-test-1/_doc
{
  "field_1": "value1",
  "field_2": "value2"
}

POST /data-test-2/_doc
{
  "field_1": "value3",
  "field_2": "value4"
}

POST /data-test-2/_doc
{
  "field_1": "value5",
  "field_2": "value6"
}

Discover

Clicking either the + or - filtering controls for value4 or value6 results in 0 documents, a query_shard_exception and message:

There are many ways and valid reasons this could happen. Just having the field with value and the filtering controls in place could leave a user thinking the filter should work. Can the + and - controls be replaced with an info tip or something indicating why?

[111andre111]

Probably related: #154714

[111andre111]

related: #171059