Implement feature flag on client

[junjun107]

The goal of this ticket is to determine whether the current user is authorized to access a particular feature. It replaces the old environment variable feature flag system.

Backend:

• Update getByEmail in account-service to retrieve both user details and their feature names list.
• Update features types

Frontend:

• Modified useFeatureFlag hook to use userContext to check if current user has access to the specific feature