Added authentication and authorization, updated dependency injections, removed hard-coded connection string

SchengenVisaApi/Domains/Users/Role.cs

@@ -0,0 +1,13 @@
+namespace Domains.Users
+{
+    /// Role of <see cref="User"/>
+    public enum Role
+    {
+        /// Requests visa applications
+        Applicant,
+        /// Approves or declines applications
+        ApprovingAuthority,
+        /// Manages approving authorities
+        Admin
+    }
+}

SchengenVisaApi/Domains/Users/User.cs

@@ -0,0 +1,14 @@
+namespace Domains.Users
+{
+    public class User : IEntity
+    {
+        /// Unique Identifier of <see cref="User"/>
+        public Guid Id { get; private set; } = Guid.NewGuid();
+
+        public Role Role { get; set; }
+
+        public string Email { get; set; } = null!;
+
+        public string Password { get; set; } = null!;
+    }
+}