Enhancements for Brand Alignment layout

[pgwillia]

• There may be ways to improve the load time of pages using this layout as well, Pagespeed Insights could help analyse this once this is live with a page containing content.

https://developers.google.com/privacy-sandbox/3pcd is worth noting too:

Originally posted by @ConnorSheremeta in #594 (review)

• Page layout may be unexpected due to Quirks Mode Adding new layout #594 (comment)
• Redundant inclusion of bootstrap v5 Adding new layout #594 (comment)