HTML/JS sidebar: shipped slide templates don't work

[nikslor]

Describe the bug
In the impress sidebar of online (and also iOS, probably other platforms as well) there is a section where a user can choose an integrated slide master template. However, since the HTML/JS rework, those templates can't be selected.

To Reproduce
Steps to reproduce the behavior:

1. Create/open a slidedeck in online
2. Open the "Master Slides" sidebar
3. Scroll down to 'Available for use'
4. Select one of the integrated templates

Expected behavior
The selected template should be applied

Actual behavior
The template doesn't get applied

Screenshots

Online

• Firefox: 92.x
• OS: Linux
• Version: current version on https://staging.eu.collaboraonline.com/nextcloud/index.php - 21.06.1.0 (git hash: e5bbfc6) Served by: 7d76d5c7

[eszkadev]

fix in core: https://gerrit.libreoffice.org/c/core/+/123037

[eszkadev]

fixed in core, should be visible in the next snapshot