Refactor query handlers to remove NotFoundException

Refactored query handlers (`ReadProfileViewQueryHandler`,
`ReadRecActionViewQueryHandler`, and `ReadResultViewQueryHandler`)
to return empty results instead of throwing `NotFoundException`
when no data is found. Simplified the logic by removing null
or empty result checks and directly returning mapped results.

Updated corresponding test cases to align with the new behavior:
- Removed `try-catch` blocks for `NotFoundException`.
- Adjusted assertions to handle empty results.
- Removed the test case for `ReadRecActionViewQuery` that
  expected `NotFoundException`.

This change reflects a design shift to let the calling code
handle empty results instead of relying on exceptions.

tests/ReC.Tests/Application/RecActions/RecActionQueryTests.cs

@@ -30,34 +30,11 @@ public class RecActionQueryTests : RecApplicationTestBase
         var (sender, scope) = CreateScopedSender();
         using var _ = scope;
 
-        try
+        var actions = await sender.Send(new ReadRecActionViewQuery
         {
-            var actions = await sender.Send(new ReadRecActionViewQuery
-            {
-                ProfileId = profileId
-            });
+            ProfileId = profileId
+        });
 
-            Assert.That(actions, Is.Not.Empty);
-            Assert.That(actions.All(a => a.ProfileId == profileId));
-        }
-        catch (NotFoundException)
-        {
-            Assert.Pass("NotFound is acceptable when test data is unavailable");
-        }
-    }
-
-    [Test]
-    public void ReadRecActionViewQuery_with_unknown_profile_throws_not_found()
-    {
-        var (sender, scope) = CreateScopedSender();
-        using var _ = scope;
-
-        var invalidProfileId = long.MaxValue;
-
-        Assert.ThrowsAsync<NotFoundException>(async () =>
-            await sender.Send(new ReadRecActionViewQuery
-            {
-                ProfileId = invalidProfileId
-            }));
+        Assert.That(actions.All(a => a.ProfileId == profileId));
     }
 }