refactor(Button): align with Mantine API using leftSection/rightSection

[beaucalvez]

Summary

• Refactored Button component to use leftSection/rightSection props instead of leftIcon/rightIcon to align with Mantine v7+ official API
• Updated Button.figma.tsx Code Connect to use hasLeftSection/hasRightSection properties
• Fixed CloseButton.figma.tsx to import from local Design System component
• Updated Figma URL references to correct node IDs

Changes

Button Component

• Removed leftIcon and rightIcon props from DSButtonProps interface
• Added leftSection and rightSection props with improved documentation
• Updated component implementation to use Mantine-aligned prop names
• Fixed typo in JSDoc example (</ADDSButton> → </Button>)
• Updated CSS class logic from hasLeftIcon to hasLeftSection

Button Code Connect

• Updated Figma node URL to correct ID: 5331-12700
• Renamed props from hasIconLeft/hasIconRight to hasLeftSection/hasRightSection
• Updated documentation to reflect generic content support vs icon-specific

CloseButton Code Connect

• Changed import from @mantine/core to local DS component ./CloseButton
• Updated Figma tracking parameter for consistency

Benefits

• Better Mantine alignment: Uses official Mantine v7+ API conventions
• More flexible: Props are named for generic content, not just icons
• Clearer intent: Documentation now reflects that sections can contain any React content (badges, text, icons, etc.)
• Correct Code Connect: Both Button and CloseButton now map to correct Figma nodes

Test Plan

• Button Code Connect published successfully to Figma
• CloseButton Code Connect published successfully to correct node
• Verify Button renders correctly with leftSection/rightSection props
• Verify all Button variants still work as expected
• Test in Figma that code examples generate correctly