Add permissions for API endpoints

[Frama-99]

• Users (api/v1/users) is only accessible by admin
• Equipment items (api/v1/equipment-items), equipment types (api/v1/equipment-types), equipment types with availability (api/v1/equipment-type-times, needs Create new API GET endpoint for fetching equipment items specific to a time range #118 ), and categories (api/v1/equipment-categories) should be viewable by all users that are authenticated (admin and members)
• Equipment items, types, and categories should be editable only by admin
• List of all equipment requests (api/v1/equipment-requests-admin) should be viewable only by admin
• Equipment request specific to a member (api/v1/equipment-requests) should be viewable and editable only by that member and by admin