Resolve "Wiki page attachments not rendered properly"

What does this MR do?

We previously detected unconverted markdown link urls in wikis that have a space. Images also have the same problem. So we detect them and replace the space with a %20

What are the relevant issue numbers?

Closes #51196 (closed)

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• Tests added for this feature/bug
• Conforms to the code review guidelines
• Conforms to the merge request performance guidelines
• Conforms to the style guides
• Conforms to the database guides