Double escaping in views attachment titles

Problem/Motivation

Views attachment titles are double escaped.

The title as entered

The title displayed in the admin section of the view.

The title displayed in the preview section.

Note that this issue was committed and reverted.

Steps to reproduce

1. Create an attachment display for a view
2. Create a title with special characters
3. View the title in the preview section of the view

Proposed resolution

TBA

Remaining tasks

Test
Patch
Review
Commit

User interface changes

Yes - Add update to date screeenshots here

API changes

N/A

Data model changes

N/A

Release notes snippet

N/A