Add return grant button to grant cards (#175)

[rocristoi]

Summary of the problem

Problem #175 - there is no button to return grants on the mobile app, this adds one.

Describe your changes

I've added a "Cancel Grant" button to each Grant Card. When clicked, it displays a warning message—just like the one on HCB Web—informing the user about the action they're about to take. The user can either cancel or confirm the action. If confirmed, the grant is canceled using the new HCB V4 API endpoint: /api/v4/card_grants/:id/cancel. A spinner appears on the button to provide feedback to the client and prevent duplicate API calls, and an error alert is shown if the API request fails.

Checklist

• Descriptive PR title (Does the title explain the changes in a concise manner?)
• Tag related issues so they auto-close on merge
• Easily digestible commits (Are the commits small and easy to understand?) video
• CI passes (Do the GitHub checks pass?)
• Tested by submitter before requesting review (Does it work in development iOS/android? )

Simulator.Screen.Recording.-.iPhone.16.Pro.-.2025-05-25.at.12.27.55.mp4

[Luke-Oldenburg]

Does this work for managers too? If so the button should appear as cancel grant to them unless it's their own grant also.

[rocristoi]

I'll look into this later this week.

[rocristoi]

Added a check to see if the user is the card's org manager and stored it inside a useState called isOrgManager. The screenshot represents what a manager sees.

[thedev132]

LGTM :) You didn't need to add isOrgManager you can just say if they aren't the cardholder as this is cleaner towards admins. Made the fixes accordingly