Mermaid Output in doxygen not displaying correctly

When doxygen outputs html there's a bug in the render that it's not generated correctly, this is a known bug with doxygen.
- We need to fix the issue in the github code, or check that someone else hasn't fixed it.
- raise a ticket on doxygen github, and submit our change
- In the meantime until the uprevision, we need to keep applying the patch to the code.
- It may be rendered correctly if we followed the same fix that was applied for plantUML.

rdkcentral / hal-doxygen