Fix output display in api4 explorer

[colemanw]

Overview

Fixes the display of api explorer output which contains html entities.

Before

Output such as <i>test</i> appears as italicized text in the explorer.

After

Output displays html entities properly.

Comments

Easiest way to test this is by doing contact.get in the api explorer, add a text field such as first_name to the WHERE clause, and type something like <i>test</i>. Observe the generated code below.

[civibot]

(Standard links)

• If this is your first pull-request for CiviCRM, please browse CONTRIBUTING.md for information about the development and testing processes.
• If you are reviewing this pull-request, you may wish to consult the test sites and the Review Standards (long template, short template).

[eileenmcnaughton]

unrelated fail