[Feature] rank_feature field type is supported in OS but not in OSD

Describe the bug

A rank_feature field behaves as expected when running search queries with it, however it is displayed as unknown in both discovery page and Stack Management -> Index patterns page. The rank_feature feature seems to be added or fixed in this OpenSearch issue https://github.com/opensearch-project/OpenSearch/issues/977, but not in OpenSearch Dashboards.

To Reproduce

Created the Index test with the Following Mapping:

PUT /test
{
"mappings": {
"properties": {
  "pagerank": {
    "type": "rank_feature"
  },
  "url_length": {
    "type": "rank_feature",
    "positive_score_impact": false
  },
  "topics": {
    "type": "rank_features"
  }
}
}
}

Indexed following Two Documents -


PUT /test/_doc/1?refresh
{
"url": "https://en.wikipedia.org/wiki/2016_Summer_Olympics",
"content": "Rio 2016",
"pagerank": 50.3,
"url_length": 42,
"topics": {
"sports": 50,
"brazil": 30
}
}

PUT /test/_doc/2?refresh { "url": "https://en.wikipedia.org/wiki/2016_Brazilian_Grand_Prix", "content": "Formula One motor race held on 13 November 2016", "pagerank": 50.3, "url_length": 47, "topics": { "sports": 35, "formula one": 65, "brazil": 20 } }

3. Could Run the below Query, without any exception/error.

GET /test/_search { "query": { "rank_feature": { "field": "pagerank", "linear": {} } } }


4. On creating the Index Pattern test*, could observe that fields like - pagerrank, topics had type as unknown. As seen below -
![image](https://user-images.githubusercontent.com/99116880/172897966-a464d417-631f-4aa3-96ea-c13c0d156bc2.png)

5. On the Discover Page, also could see the Type was unknown for the mentioned fields.
![image](https://user-images.githubusercontent.com/99116880/172898047-abd785ae-4679-4aac-a9ec-5db4fd233d90.png)

**Expected behavior**
`rank_feature` should be recognized in OSD

**OpenSearch Version**
1.2

**Dashboards Version**
1.2

opensearch-project / OpenSearch-Dashboards

[Feature] rank_feature field type is supported in OS but not in OSD #1712