UI: Move JSON validation and prettifying into JsonEditor

[ABiscuitttt]

The validate-and-prettify logic for JSON input lived in CreateAssetEventModal with a TODO asking to move it into the shared JsonEditor. It now lives behind new optional prettify/onError props so any JSON input in the UI can opt in instead of re-implementing it.

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[boring-cyborg]

Congratulations on your first Pull Request and welcome to the Apache Airflow community! If you have any issues or are unsure about any anything please check our Contributors' Guide
Here are some useful points:

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[boring-cyborg]

Awesome work, congrats on your first merged pull request! You are invited to check our Issue Tracker for additional contributions.

[github-actions]

Backport successfully created: v3-3-test

Note: As of Merging PRs targeted for Airflow 3.X
the committer who merges the PR is responsible for backporting the PRs that are bug fixes (generally speaking) to the maintenance branches.

In matter of doubt please ask in #release-management Slack channel.

Status	Branch	Result
✅	v3-3-test