fix(no-code-editor): preserve cron quotes across edits

[Ashutoshbind15]

Fixes kestra-io/kestra#14052

Summary of changes:

• Add a util function to post-process the generated yaml string and add quotations to the cron expressions, when not present
• Add the needed tests

Tests and Build Info:

• Tests pass for both ui-libs and the main repo
• npm run build passes for both (after using the locally built ui-libs as dependency)
• Lints show no errors on the changes proposed

screenrecording-2026-01-13_21-51-32.mp4

[elevatebart]

Even though it's a lot of tests for a simple feature I prefer too much tests than less.

A few nitipcks but overall Good waork.

Thank you !

[Ashutoshbind15]

Have resolved the review comments @elevatebart, you may re-review/merge as needed.

Thank you!