Admins can customize Analytics model names.

The default model names are obtained from the lang pack, but multilang tags for custom model names are dropped by PARAM_NOTAGS in core_analytics_inplace_editable().

Replacing the line:

        $model->rename(clean_param($newvalue, PARAM_NOTAGS));

with the line:

        $model->rename(clean_param($newvalue, PARAM_TEXT));

will fix the problem.

Reproduction Steps:

1. Make sure multilang filter is enabled and a lang pack (say German) is installed.
2. Make sure Analytics are enabled (in "Site administration" > "General" tab > "Advanced features").
3. Open Analytics models page by "Site administration" > "General" tab > "Analytics models".
4. Click any model name (say "Upcoming activities due") and type "<span class="multilang" lang="en">Example</span><span class="multilang" lang="de">Beispiel</span>", then Enter.
5. You see the model name is "ExampleBeispiel".