[Issue] Replace JSON serializer with JSON Hex Tag (User module)

[m2-assistant]

This issue is automatically created based on existing pull request: #31359: Replace JSON serializer with JSON Hex Tag (User module)

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Description (*)

The serializer injected into the View Model is being used to serialize data for the Store views.
When trying to use the data serialized with a regular Serializer, it ends up on crash when you have unescaped elements in your contents. That is why JsonHexTag class was introduced.

The goal of this PR is to replace the JSON serializer with the more useful/accurate one.

Related Pull Requests

Fixed Issues (if relevant)

1. Fixes magento/magento2#<issue_number>

Manual testing scenarios (*)

1. ...
2. ...

Questions or comments

Contribution checklist (*)

• Pull request has a meaningful description of its purpose
• All commits are accompanied by meaningful commit messages
• All new or changed code is covered with unit/integration tests (if applicable)
• All automated tests passed successfully (all builds are green)

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed after 14 days if no further activity occurs. Is this issue still relevant? If so, what is blocking it? Is there anything you can do to help move it forward? Thank you for your contributions!

[dverkade]

This is not a stale issue, PR is in progress and issue is ready for work. This issue can't be closed automatically.

[github-jira-sync-bot]

✅ Jira issue https://jira.corp.adobe.com/browse/AC-9489 is successfully created for this GitHub issue.

[m2-assistant]

✅ Confirmed by @engcom-Lima. Thank you for verifying the issue.
Issue Available: @engcom-Lima, You will be automatically unassigned. Contributors/Maintainers can claim this issue to continue. To reclaim and continue work, reassign the ticket to yourself.