Refactor Email to EmailContext across codebase

Replaced the `Email` record with the new `EmailContext` record to introduce additional context and functionality in email handling. Updated property definitions to distinguish between .NET Framework (`set`) and other frameworks (`init`).

Modified `SendingEmailEvent` to use `EmailContext` for the `Mail` property. Updated mappings in `EmailMappingProfile` to map `SendEmailCommand` to `EmailContext`. Adjusted `SendEmailCommandHandler` to use `EmailContext` when mapping requests.

Refactored `EmailSender` to use `EmailContext` in its `Send` method, including updates to method signatures and documentation. Updated all related test classes (`EmailSenderTests`, `EmailSenderUrlOverloadTests`, `SendingEmailPublisherTests`) to validate the behavior of `EmailContext`, ensuring consistency and thorough testing of the transition.

These changes ensure compatibility across frameworks and improve the maintainability of the email handling process.

src/presentation/DigitalData.MessagingService.Client/EmailSender.cs

@@ -113,13 +113,13 @@ public static class EmailSender
     /// Thrown when <see cref="ConnectRabbitMq(Action{RabbitMqConfiguration}, OnReconnect)"/> has not been called prior to sending.
     /// </exception>
     /// <remarks>
-    /// This method maps <see cref="Email"/> to <see cref="SendingEmailEvent"/>,
+    /// This method maps <see cref="EmailContext"/> to <see cref="SendingEmailEvent"/>,
     /// then resolves <see cref="ISendingEmailPublisher"/> from the internal
     /// service provider and calls <c>EnqueueAsync</c> in a fire-and-forget manner.
     /// Ensure that any unhandled exceptions from the async operation are handled
     /// at the publisher level.
     /// </remarks>
-    public static void Send(Email email)
+    public static void Send(EmailContext email)
     {
         if(!IsConnected)
             throw new InvalidOperationException("Messaging service is not connected. Call ConnectRabbitMq first.");