[beta1] ⚠️ Fix compatibility with layout builder

Other tasks to do in the scope of this issue:

• Compatibility with tokens browser pop-in
• Remove harmful raw filter from alert, nav, tabs & accordion patterns

Big commit pushed to road_to_first_beta branch : 14e6205254495f9b85d619650036ebcee9a1aab1

Remaining work about patterns:

• Download block: description is wrapping everything and preventing clicks
• Download link: details is wrapping stuff and preventing clicks
• Navbar: |raw() filter, but let's wait for ✨ Add links setting type Needs review
• Skiplinks: hidden by default (position absolute + trasnform) in DSFR CSS
• Tabs: |raw() filter, but we may need to refactor it first, because of the messy Drupal menu-local-tasks & menu-local-task

And also:

• Blocking MR: tokens in textfields are not resolved
• CSS conflict in tokens browser pop-in
• Check compatibility with big-pipe

"Blocking MR: tokens in textfields are not resolved" is fixed