Add support for linear in rank_feature

[Hronom]

Describe the bug
rank_feature throw exception when using linear function
https://www.elastic.co/guide/en/elasticsearch/reference/current/query-dsl-rank-feature-query.html#rank-feature-query-linear

Support for apache/lucene-solr#2051

To Reproduce

1. Create index

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

2. Add test docs

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
  }
}

PUT /test/_doc/3?refresh
{
  "url": "https://en.wikipedia.org/wiki/Deadpool_(film)",
  "content": "Deadpool is a 2016 American superhero film",
  "pagerank": 50.3,
  "url_length": 37,
  "topics": {
    "movies": 60,
    "super hero": 65
  }
}

3. Execute query

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

Expected behavior
As described here https://www.elastic.co/guide/en/elasticsearch/reference/current/query-dsl-rank-feature-query.html#rank-feature-query-linear

[Hronom]

Workaround elastic/elasticsearch#49859 (comment)

[dblock]

Looks like we need to reimplement elastic/elasticsearch#67670