Update Policy and Role side panels to the new design

# Chore ## Describe the chore While going through the accessibility-related ESLint errors, I came across two side panels that are still using the old design: - PolicyDetailsV2.tsx (screen: Database / Policies / Create Policy) <img width="1979" height="1246" alt="Image" src="https://github.com/user-attachments/assets/3a15e40d-aed9-446f-b8a5-66e910e39e01" /> - CreateRolePanel.tsx (screen: Database / Roles / Add Role) <img width="1987" height="1256" alt="Image" src="https://github.com/user-attachments/assets/e8fa74f1-fa35-4cb4-9ad0-5065010e8876" /> Would you like me to update their design to use the design system, using this side panel? <img width="1990" height="1250" alt="Image" src="https://github.com/user-attachments/assets/b2abdfcf-f138-4387-ae32-889270c9b464" /> ## Additional context This change will be limited to migrating the existing side panels to the new design system. No other visual changes will be introduced.