Support icons

[AdinathBorse]

Support Icons

Changes Made

Frontend (commbank-web)

• types.ts — Added icon: string | null to the Goal interface
• GoalCard.tsx — Displays the goal's icon on the goal card
• GoalManager.tsx — Implemented emoji picker; wired pickEmojiOnClick
  to call updateGoalApi so icon changes persist after client refresh

API Layer

• lib.ts — Added updateGoal() PUT request to PUT /api/Goal/{goalId}

Tests

• GoalControllerTests.cs — Added GetForUser test to verify the
  GetGoalsForUser route returns goals filtered by the correct user ID