Increase component border radius

Per the decision in https://gitlab.com/gitlab-org/gitlab/-/issues/568908#note_2763982372, component border radius will be increased to match the project studio exploration.

The following design tokens and components are addressed in !5153 (merged):

• Action design tokens
• Control design tokens
• Button
• Card
• Form controls
• Modal
• Pagination

The following design tokens and components are addressed in !5169 (merged):

• Feedback design tokens
• Alert
• Banner
• Popover
• Toast
• Tooltip

Other:

• Filtered search (!5199 (merged)).
• Token component (!5200 (merged))

Remaining items to address:

• Shared components
• [-] Components that use deprecated styles, but that aren't deprecated themself (like GlFormCombobox) See #3158 (closed)

The following components are addressed in Figma via independent branches (current approach is manual updates sans variables until design tokens can be reliably synced with Figma variables):

Warning

Order of completion is important because contextual overrides may be necessary!

• Focus ring (should support multiple radii — probably just needs to add a larger one)
• Button (excluding link variant)
• Form controls (override radius for nested close and clear buttons)
  • Base prefix / suffix (when changes aren't coming from button)
  • Base input child
• Alert
• Banner
• Button group
• Date picker (only change the base calendar container, the date component should remain unchanged)
• Modal
• Pagination
• Popover
• Sorting
• Toast
• Token
• Tooltip