[Wiki] & and other special chars in page slug

Summary

It's possible to add & and other special chars to the slug of a wiki page. Problem is, that the slug is used in the auto-generated page title and isn't escaped correctly.

Steps to reproduce

• Add a new wiki page with & in the page slug
• Get a pretty & in the auto-generated page title.

What is the current bug behavior?

The & isn't escaped properly

What is the expected correct behavior?

A & instead of &