(Outdated) [Index Management] Improve UX of mappings editor

[ElenaStoeva]

Renamed the branch which closed this PR. Here is the updated PR: #152730

Summary

This PR implements the short-term solution proposed in #52708 (comment) - disabling the Update button of the mappings editor form when no changes have been made by the user and, when there are saveable changes, displaying some text guiding the user to review all of the field's settings and a tooltip that provides more context.

This implementation uses the useFormIsModified hook from the form lib (https://docs.elastic.dev/form-lib/core/use-form-is-modified) which didn't work as expected for this use case so a fix to this hook is added as well. I verified that all other forms that use this hook (the field editor from Data Views and the Connector editor) are working fine with the added fix to the hook. Also, several mappings editor jest tests are modified to match the new scenario and a new one was added to test if the Update button is enabled/disabled as supposed.

How to test

1. Go to Stack Management -> Index Management -> Index Templates
2. Create a new index template with some mappings fields.
3. Start editing the created index template and go to the Mappings step of the form wizard.
4. Click on the Edit button of any of the fields.
5. Verify that the Update button is disabled.
6. Verify that any change on the form enables the Update button and displays the "Review all settings before updating" text with a tooltip.

Screen.Recording.2023-03-06.at.15.19.57.mov

Checklist

• Unit or functional tests were updated or added to match the most common scenarios
• Any UI touched in this PR is usable by keyboard only (learn more about keyboard accessibility)
• Any UI touched in this PR does not create any new axe failures (run axe in browser: FF, Chrome)

[elasticmachine]

Pinging @elastic/platform-deployment-management (Team:Deployment Management)

[ElenaStoeva]

@elasticmachine merge upstream

[kibana-ci]

💛 Build succeeded, but was flaky

• Buildkite Build
• Commit: 8e19ee0

Failed CI Steps

• FTR Configs #29

Test Failures

• [job] [logs] FTR Configs #29 / machine learning - anomaly detection create jobs from dashboard map can create a geo job from map with single layer
• [job] [logs] FTR Configs #29 / machine learning - anomaly detection create jobs from lens "after each" hook for "can create a single metric job from vis with single layer"
• [job] [logs] FTR Configs #29 / machine learning - anomaly detection create jobs from lens with wizard can create multi metric job from vis with single layer

Metrics [docs]

Async chunks

Total size of all lazy-loaded chunks that will be downloaded as the user navigates the app

id	before	after	diff
indexManagement	524.7KB	525.2KB	+506.0B

Page load bundle

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

id	before	after	diff
esUiShared	152.4KB	152.4KB	+76.0B

Unknown metric groups

ESLint disabled line counts

id	before	after	diff
esUiShared	11	12	+1
securitySolution	428	430	+2
total			+3

Total ESLint disabled count

id	before	after	diff
esUiShared	11	12	+1
securitySolution	506	508	+2
total			+3

History

• 💚 Build #111449 succeeded 13a94c5

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

cc @ElenaStoeva