Encoding error in json response for ACL messages for non-english languages

[Ruslan-Aleev]

Bug report

Summary

ACL can give an incorrect error message, for example, this.

It is already not very clear to the end user what exactly the ACL error is.

But if the manager panel is not in english, then json displays messages in incorrect encoding, i.e. it is not even clear that the error is related to ACL.

It also makes sense to display specific information in window, for example, the permission that is required (view_template, list_template etc).

Potential solution

Use second parameter for json_encode (available as of php 5.4) to avoid encoding problems:
json_encode($data, JSON_UNESCAPED_UNICODE);

Step to reproduce

Change the language in the manager panel, for example, to russian. Create a user with access policy with view_template disabled in the policy template and try to edit resource.

Expected behavior

Display readable messages.

Related issue(s)/PR(s)

#14506 (Error Messages)

Environment

MODX 2.x>

[Ruslan-Aleev]

Fixed in #15402