Add global exception handling middleware

Introduced `ExceptionHandlingMiddleware` to handle exceptions globally, log them, and return appropriate HTTP responses with JSON error messages.

- Added `HandleExceptionAsync` for exception processing.
- Handled `BadRequestException` (400) and `NotFoundException` (404).
- Included default handling for unhandled exceptions (500).
- Marked middleware as `[Obsolete]` with a note to use `DigitalData.Core.Exceptions.Middleware`.
- Added necessary `using` directives and XML documentation.

src/ReC.API/Middleware/ExceptionHandlingMiddleware.cs

@@ -0,0 +1,84 @@
+using DigitalData.Core.Exceptions;
+using System.Net;
+using System.Text.Json;
+
+namespace ReC.API.Middleware;
+
+//TODO: Fix and use DigitalData.Core.Exceptions.Middleware
+/// <summary>
+/// Middleware for handling exceptions globally in the application.
+/// Captures exceptions thrown during the request pipeline execution,
+/// logs them, and returns an appropriate HTTP response with a JSON error message.
+/// </summary>
+[Obsolete("Use DigitalData.Core.Exceptions.Middleware")]
+public class ExceptionHandlingMiddleware
+{
+    private readonly RequestDelegate _next;
+    private readonly ILogger<ExceptionHandlingMiddleware> _logger;
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="ExceptionHandlingMiddleware"/> class.
+    /// </summary>
+    /// <param name="next">The next middleware in the request pipeline.</param>
+    /// <param name="logger">The logger instance for logging exceptions.</param>
+    public ExceptionHandlingMiddleware(RequestDelegate next, ILogger<ExceptionHandlingMiddleware> logger)
+    {
+        _next = next;
+        _logger = logger;
+    }
+
+    /// <summary>
+    /// Invokes the middleware to handle the HTTP request.
+    /// </summary>
+    /// <param name="context">The HTTP context of the current request.</param>
+    /// <returns>A task that represents the asynchronous operation.</returns>
+    public async Task InvokeAsync(HttpContext context)
+    {
+        try
+        {
+            await _next(context); // Continue down the pipeline
+        }
+        catch (Exception ex)
+        {
+            await HandleExceptionAsync(context, ex, _logger);
+        }
+    }
+
+    /// <summary>
+    /// Handles exceptions by logging them and writing an appropriate JSON response.
+    /// </summary>
+    /// <param name="context">The HTTP context of the current request.</param>
+    /// <param name="exception">The exception that occurred.</param>
+    /// <param name="logger">The logger instance for logging the exception.</param>
+    /// <returns>A task that represents the asynchronous operation.</returns>
+    private static async Task HandleExceptionAsync(HttpContext context, Exception exception, ILogger logger)
+    {
+        context.Response.ContentType = "application/json";
+
+        string message;
+
+        switch (exception)
+        {
+            case BadRequestException badRequestEx:
+                context.Response.StatusCode = (int)HttpStatusCode.BadRequest;
+                message = badRequestEx.Message;
+                break;
+
+            case NotFoundException notFoundEx:
+                context.Response.StatusCode = (int)HttpStatusCode.NotFound;
+                message = notFoundEx.Message;
+                break;
+
+            default:
+                logger.LogError(exception, "Unhandled exception occurred.");
+                context.Response.StatusCode = (int)HttpStatusCode.InternalServerError;
+                message = "An unexpected error occurred.";
+                break;
+        }
+
+        await context.Response.WriteAsync(JsonSerializer.Serialize(new
+        {
+            message
+        }));
+    }
+}