Moved entity configurations to their own folder

PostFundManagement.Domain/Configuration/Email/Account.cs

@@ -0,0 +1,8 @@
+namespace PostFundManagement.Domain.Configuration.Email;
+
+public sealed class Account
+{
+    public string? Username { get; set; }
+
+    public string? Password { get; set; }
+}

PostFundManagement.Domain/Configuration/Email/SmtpSettings.cs

@@ -0,0 +1,12 @@
+namespace PostFundManagement.Domain.Configuration.Email;
+
+public sealed class SmtpSettings
+{
+    public Account? Credentials { get; set; }
+
+    public int Port { get; set; }
+
+    public string? Host { get; set; }
+
+    public bool UseSsl { get; set; }
+}