Add support for dense_vector and sparse_vector field mappings

[codebrain]

Relates: elastic/elasticsearch#33022

Client should support new field datatypes

• Rank Feature (see Add rank_feature, rank_features field datatypes and rank_feature query #3938)
• Rank Features (see Add rank_feature, rank_features field datatypes and rank_feature query #3938)
• Dense Vector - https://www.elastic.co/guide/en/elasticsearch/reference/7.x/dense-vector.html
• Sparse Vector - https://www.elastic.co/guide/en/elasticsearch/reference/7.x/sparse-vector.html

[russcam]

Both Sparse and Dense vector are marked as experimental, so I don't think should be implemented at this stage.

[russcam]

Split out rank_feature, rank_features and rank_feature query into #3938

[PharaonHub]

Any progress milestones on dense vector mapping? Thanks.

[russcam]

Dense vector fields were marked as GA in 7.6.0 (elastic/elasticsearch#49120) so we're good to add them to the high level client. We'll look to get them in the next release.

Sparse vector have been deprecated and will be removed so don't think we should implement these.