Issue Summary

Exporting umlaut characters using export_view API encodes characters incorrectly

Steps to Reproduce

1. Create a new page;
2. Add a macro which contents are Umlaut characters (e.g. "äöü ßÄÖ ÜÖ")
3. Export the page using /wiki/rest/api/content?expand=body.storage,body.view,body.export_view

Expected Results

The representation encodes characters correctly in UTF-8 and the output shows the same characters contained in the macro.

Actual Results

The characters are incorrectly encoded resulting in "��� ��� ��"

Workaround

Use the native PDF exporter as an alternative if possible, as it currently exports them correctly.