Fix literal interpolation for curly brackets for Translation Strings

[azrikahar]

Description

Fixes #16164

#15872 applied the general literal interpolation fix for Translation Strings. However as we can use them in custom extensions and have the flexibility of using named formatting (eg. my {custom} string), this PR opts to keep curly brackets intact for Translations Strings.

For example, when we have the following translation string setup:

and when we subsequently use named formatting in our extension such as t("custom_string", { first: "My", second: "test here" }), it will now be formatted correctly:

Before	After

Type of Change

• Bugfix
• Improvement
• New Feature
• Refactor / codestyle updates
• Other, please describe:

Requirements Checklist

• New / updated tests are included
• All tests are passing locally
• Performed a self-review of the submitted code

If adding a new feature:

• Documentation was added/updated. PR:

[br41nslug]

LGTM! tested with a custom module using translation strings with placeholders which do stay intact now as expected in this branch.