feat: implement message deletion functionality and improve draft handling

- Added `MoveToTrash` method in `WebmailRepository` to move messages to the Trash folder instead of deleting them permanently.
- Introduced `handleDelete` method in `mailAPI` to handle message deletion requests from the client.
- Updated router to include a new route for message deletion.
- Enhanced the compose page to manage draft integrity, ensuring drafts are correctly associated with sent messages.
- Implemented UI changes to allow users to delete messages from the mail folder view.
- Added tests to verify the correct behavior of message deletion and draft handling.
- Updated database migration scripts to reconcile folder counters and ensure accurate unread counts.
- Added tests for TLS-RPT report parsing and webmail repository functionalities.

migrations/0007_reconcile_folder_counters.down.sql

@@ -0,0 +1,5 @@
+-- Irreversible by nature: this migration replaced incorrect counter values and
+-- added the flags that describe what a message is. Restoring the old numbers
+-- would mean restoring known-wrong data, and dropping the \Seen and \Draft
+-- flags would discard read state the user may since have set by hand.
+SELECT 1;