fix: Avoid Global styles / Garden styles clash

[Fredx87]

Description

This PR fixes the conflict between the global styles defined in the global CSS files with the styles defined by Garden.

There were some issues caused by the global styles applied to form elements that were also applied to Garden components.

• All forms rendered in Curlybars now have the hbs-form class applied
• All form element styles are scoped inside the hbs-form class or the search class for the form associated to the search helper
• Removed ad-hoc fixes in the New Request Form components

Checklist

• 📗 all commit messages follow the conventional commits standard
• ⬅️ changes are compatible with RTL direction
• ♿ Changes to the UI are tested for accessibility and compliant with WCAG 2.1.
• 📝 changes are tested in Chrome, Firefox, Safari and Edge
• 📱 changes are responsive and tested in mobile
• 👍 PR is approved by @zendesk/vikings