Fix: Remove top and bottom margin 0 on full width patterns

[juanfra]

Description

Fixes #328

This PR removes the margin top/bottom set to zero for full-width patterns.
It also updates the landing pages to be contained by a group with a block gap of zero.

Bonus:

• Add description to testimonials patterns.
• Indent several patterns.

Screenshots

N/A

Testing Instructions

1. Create a page.
2. Add the following patterns
   • Banner with book description
   • Banner with description and images grid
   • Clients section
   • Centered link and social links
   • Contact: Info and locations
   • Cover with big heading
   • Call to action with book links
   • Call to action with locations
   • Pricing two columns
   • Events – List with Call to Action
   • Events three columns with event images and titles
   • Grid with videos
   • Heading and paragraph with image on the right
   • Hero Centered Heading
   • Hero podcast
   • Link in bio with tight margins
   • Newsletter Sign Up
   • Poster-like section
   • Services - Subscriber only section
   • Services - Three-column boxed pricing table
   • Services - Three Columns
   • Review with large image on right
   • Three column layout with 6 testimonials
   • Two columns with avatar
   • FAQs
   • Two Headings and a List
3. Confirm that these patterns no longer have a margin top/bottom set to zero.

[github-actions]

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[github-actions]

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Co-authored-by: juanfra <[email protected]>
Co-authored-by: beafialho <[email protected]>
Co-authored-by: maneshtimilsina <[email protected]>
Co-authored-by: carolinan <[email protected]>

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