## Summary

Closes elastic#171225

- Highlights secrets during package policy creation with a distinct
background and icon
- Add tooltip + docs link for secrets where appropriate
- Detect "new secrets" during policy upgrade and alert the user in a
separate callout

## To do
- [x] Fix any failing tests
- [x] Add tests for "new secrets" detection logic

## Screenshots

![image](https://github.com/elastic/kibana/assets/6766512/e943a3e8-68db-40eb-a5c3-b108e7d299ff)

![image](https://github.com/elastic/kibana/assets/6766512/751bbe50-7553-4dcc-a8dc-b9802f331013)

![image](https://github.com/elastic/kibana/assets/6766512/6cceb4cd-0b8e-42cd-aafb-d2e3ddcd23a8)

## How to test

There's probably an easier way to do this, but this is what I did

1. Clone https://github.com/elastic/package-registry and
https://github.com/elastic/integrations
2. Add the following to `config.yml` in your package-registry repo

```yml
package_paths:
  - path/to/your/integrations/build/packages
```

3. Build a version of an integration with some `secrets: true` for
various variables. I used `1password`

```shell
cd integrations/packages/1password
# Edit `manifest.yml` or a given `data_stream/*/manifest.yml` file to change some variables to `secret: true`. Also bump the version and update `changelog.yml`
elastic-package build
```

4. Run the local package registry e.g.

```shell
cd package-registry
go run . --feature-proxy-mode=true -proxy-to=https://epr.elastic.co # makes it so you can still see EPR packages in Kibana
```

5. Update your `kibana.dev.yml` to point at your local package registry

```yml
xpack.fleet.registryUrl: http://localhost:8080
```

6. Start Kibana and Elasticsearch and install, upgrade, etc your package
in question to verify the changes

---------

Co-authored-by: David Kilfoyle <41695641+kilfoyle@users.noreply.github.com>
(cherry picked from commit 9396ef3)

# Conflicts:
#	packages/kbn-doc-links/src/get_doc_links.ts
#	packages/kbn-doc-links/src/types.ts
#	x-pack/plugins/translations/translations/fr-FR.json
#	x-pack/plugins/translations/translations/ja-JP.json
#	x-pack/plugins/translations/translations/zh-CN.json