refactor(application): Reorganize DTOs - flatten single-DTO folders

- Move EmailAccountDto.cs to Dtos/ (was in EmailAccounts/ subfolder)
- Move EmailProfileDto.cs to Dtos/ (was in EmailProfiles/ subfolder)
- Keep EmailAttachments/ (3 DTOs) and EmailHistories/ (3 DTOs) subfolders
- Update all namespace imports from Dtos.EmailAccounts/EmailProfiles to Dtos
- Simpler structure: single DTOs at root, multiple DTOs in subfolders

src/DigitalData.EmailProfiler.Application/Common/Dtos/EmailProfileDto.cs

@@ -0,0 +1,18 @@
+namespace DigitalData.EmailProfiler.Application.Common.Dtos;
+
+/// <summary>
+/// DTO for EmailProfile query results.
+/// </summary>
+public class EmailProfileDto
+{
+    public int Id { get; set; }
+    public string ProfileName { get; set; } = string.Empty;
+    public int EmailAccountId { get; set; }
+    public string? EmailAccountName { get; set; }
+    public int? ProcessId { get; set; }
+    public string? ProcessName { get; set; }
+    public int PollIntervalMinutes { get; set; }
+    public DateTime? LastPollTime { get; set; }
+    public bool IsActive { get; set; }
+    public string? Comment { get; set; }
+}