Update/wide template changes width all elements

[mlaetitia]

Changes proposed in this Pull Request

• Makes sure the new wide template max-width is set for all elements throughout. Some elements were getting a smaller width due to specific css styles overriding the content width. This PR addresses that

Testing instructions

• Open the Endorsements page (or create a new page + set it with the new No header - Wide template)
• Make sure there is some text + headings + forms in the page
• CHeck that they all become the full width of the page and aren't inhering the width of the rest of the site

Mentions #5002