[Discover] Fix _source fields of objects formatting

[dimaanj]

Summary

Fixes #123169, #127899

Before:

After:

Test:

1. You need to enable discover:searchFieldsFromSource in Advanced settings

2. Go to dev tools and use the following data to create documents

PUT actionindex
{
  "mappings": {
    "properties": {
     "action": {
                "properties": {
                    "detail": {
                        "type": "text",
                        "fields": {
                            "keyword": {
                                "type": "keyword"
                            }
                        }
                    },
                    "endpoint": {
                        "type": "keyword"
                    },
                    "method": {
                        "type": "keyword"
                    }
                }
            }
  } 
    }
}

POST actionindex/_doc
{
  "action": {
    "detail": "a test",
    "endpoint": "the_endpoint",
    "method": "the_method"
  }
} 

3. Create an data view in management and use in in Discover

4. When expanding a document action looks like this:

Checklist

• Unit or functional tests were updated or added to match the most common scenarios

[elasticmachine]

Pinging @elastic/kibana-data-discovery (Team:DataDiscovery)

[dimaanj]

@elasticmachine merge upstream

[dimaanj]

@elasticmachine merge upstream

[kibana-ci]

💚 Build Succeeded

• Buildkite Build
• Commit: 3b3b6df
• Storybooks Preview

Metrics [docs]

Page load bundle

Size of the bundles that are downloaded on every page load. Target size is below 100kb

id	before	after	diff
data	423.6KB	423.6KB	-14.0B

History

• 💚 Build #58038 succeeded d13fd75
• 💚 Build #57999 succeeded 92ec4ed
• 💔 Build #57984 failed cbeec23

To update your PR or re-run it, just comment with:
@elasticmachine merge upstream

cc @dimaanj

[kertal]

@dimaanj thx a lot for fixing this, 2 flies (issues) with 1 stone(PR) 👍 , tested locally with the demo data, 2 issues fixed, works as expected

[kibanamachine]

💔 All backports failed

Status	Branch	Result
❌	7.17	Backport failed because of merge conflicts

Manual backport

To create the backport manually run:

node scripts/backport --pr 136473

Questions ?

Please refer to the Backport tool documentation and see the Github Action logs for details

[kibanamachine]

Friendly reminder: Looks like this PR hasn’t been backported yet.
To create automatically backports add the label auto-backport or prevent reminders by adding the backport:skip label.
You can also create backports manually by running node scripts/backport --pr 136473 locally

[dimaanj]

💚 All backports created successfully

Status	Branch	Result
✅	7.17

Note: Successful backport PRs will be merged automatically after passing CI.

Questions ?

Please refer to the Backport tool documentation

[kibanamachine]

Looks like this PR has a backport PR but it still hasn't been merged. Please merge it ASAP to keep the branches relatively in sync.