This change replaces the fields parameter with stored_fields when it makes sense.
This is dictated by the renaming we made in #18943 for the search API.
The following list of endpoint has been changed to use `stored_fields` instead of `fields`:
* get
* mget
* explain
The documentation and the rest API spec has been updated to cope with the changes for the following APIs:
* delete_by_query
* get
* mget
* explain
The `fields` parameter has been deprecated for the following APIs (it is replaced by _source filtering):
* update: the fields are extracted from the _source directly.
* bulk: the fields parameter is used but fields are extracted from the source directly so it is allowed to have non-stored fields.
Some APIs still have the `fields` parameter for various reasons:
* cat.fielddata: the fields paramaters relates to the fielddata fields that should be printed.
* indices.clear_cache: used to indicate which fielddata fields should be cleared.
* indices.get_field_mapping: used to filter fields in the mapping.
* indices.stats: get stats on fields (stored or not stored).
* termvectors: fields are retrieved from the stored fields if possible and extracted from the _source otherwise.
* mtermvectors:
* nodes.stats: the fields parameter is used to concatenate completion_fields and fielddata_fields so it's not related to stored_fields at all.
Fixes#20155
This reverts commit d1f7bd97cb989d8d98e009ef71a72c7cac5077dd.
Ryan pointed out that this needs to work with the multi term query, so
additional analysis and tests should be added.
The analysis chain should be used instead of relying on this, as it is
confusing when dealing with different per-field analysers.
The `locale` option was only used for `lowercase_expanded_terms`, which,
once removed, is no longer needed, so it was removed as well.
Fixes#9978
Relates to #9973
- Removed "ok": true from response examples
- Added "created" flag to index response examples
- Replaced exists flag with found in delete response examples
