Merge pull request #25465 from Abdurrahheem:ash/parser-conf-denylist-reduce

Comments for parser denylist #25465

Relates to https://github.com/opencv/opencv/issues/21078

This PR is designed to figure out why the test in `test_onnx_conformance_layer_parser_denylist.inl.hpp` fails. Currently, conformance tests do not pass for the following reasons:

1. BOOL, INT(8, 16) types are not supported **(MAJOR)**
2. Some layers can not be created due to various reasons  **(MAJOR)**
3. Shape mismatches while creating layers  **(MAJOR)**
4. Some layers are expected to support dynamic parameter initialization  **(MAJOR)**
5. Some layers are expected to receive weight as inputs (no idea why that is needed)   **(MAJOR)**
6. Other unknown reasons

 **(MAJOR)** - These are the most frequently encountered reasons for test failure.

The style of comments is not consistent everywhere. Let's keep this PR without merging, just for our reference.
A couple of tests are commented on since they have passed on the MacOS platform.

### Pull Request Readiness Checklist

See details at https://github.com/opencv/opencv/wiki/How_to_contribute#making-a-good-pull-request

- [x] I agree to contribute to the project under Apache 2 License.
- [x] To the best of my knowledge, the proposed patch is not based on a code under GPL or another license that is incompatible with OpenCV
- [x] The PR is proposed to the proper branch
- [x] There is a reference to the original bug report and related work
- [x] There is accuracy test, performance test and test data in opencv_extra repository, if applicable
      Patch to opencv_extra has the same branch name.
- [x] The feature is well documented and sample code can be built with the project CMake

modules/dnn/test/test_onnx_conformance_layer_filter__cuda_denylist.inl.hpp

@@ -102,3 +102,5 @@
 "test_scatternd_max",
 "test_scatternd_min",
 "test_scatternd_multiply",
+"test_nllloss_NCd1d2d3d4d5_none_no_weight_expanded", // crash: https://github.com/opencv/opencv/issues/25471
+"test_pow" // accuracy issue with FP16

modules/dnn/test/test_onnx_conformance_layer_filter__openvino.inl.hpp

@@ -681,7 +681,7 @@ CASE(test_gemm_alpha)
 CASE(test_gemm_beta)
     // no filter
 CASE(test_gemm_default_matrix_bias)
-    // no filter
+    SKIP; // https://github.com/opencv/opencv/issues/25472
 CASE(test_gemm_default_no_bias)
     // no filter
 CASE(test_gemm_default_scalar_bias)