…s_with_v_exp
Add some activation conformance tests #1191
Merge with opencv/opencv#25881

…ivations_with_v_exp
dnn: optimize activations with v_exp opencv#25881
Merge with opencv/opencv_extra#1191.
This PR optimizes the following activations:
- [x] Swish
- [x] Mish
- [x] Elu
- [x] Celu
- [x] Selu
- [x] HardSwish
### Performance (Updated on 2024-07-18)
#### AmLogic A311D2 (ARM Cortex A73 + A53)
```
Geometric mean (ms)
            Name of Test              activations activations.patch activations.patch
                                                                              vs
                                                                         activations
                                                                          (x-factor)
Celu::Layer_Elementwise::OCV/CPU        115.859          27.930              4.15
Elu::Layer_Elementwise::OCV/CPU          27.846          27.003              1.03
Gelu::Layer_Elementwise::OCV/CPU         0.657           0.602               1.09
HardSwish::Layer_Elementwise::OCV/CPU    31.885          6.781               4.70
Mish::Layer_Elementwise::OCV/CPU         35.729          32.089              1.11
Selu::Layer_Elementwise::OCV/CPU         61.955          27.850              2.22
Swish::Layer_Elementwise::OCV/CPU        30.819          26.688              1.15
```
#### Apple M1
```
Geometric mean (ms)
               Name of Test                activations activations.patch activations.patch
                                                                                   vs
                                                                              activations
                                                                               (x-factor)
Celu::Layer_Elementwise::OCV/CPU              16.184          2.118               7.64
Celu::Layer_Elementwise::OCV/CPU_FP16         16.280          2.123               7.67
Elu::Layer_Elementwise::OCV/CPU               9.123           1.878               4.86
Elu::Layer_Elementwise::OCV/CPU_FP16          9.085           1.897               4.79
Gelu::Layer_Elementwise::OCV/CPU              0.089           0.081               1.11
Gelu::Layer_Elementwise::OCV/CPU_FP16         0.086           0.074               1.17
HardSwish::Layer_Elementwise::OCV/CPU         1.560           1.555               1.00
HardSwish::Layer_Elementwise::OCV/CPU_FP16    1.536           1.523               1.01
Mish::Layer_Elementwise::OCV/CPU              6.077           2.476               2.45
Mish::Layer_Elementwise::OCV/CPU_FP16         5.990           2.496               2.40
Selu::Layer_Elementwise::OCV/CPU              11.351          1.976               5.74
Selu::Layer_Elementwise::OCV/CPU_FP16         11.533          1.985               5.81
Swish::Layer_Elementwise::OCV/CPU             4.687           1.890               2.48
Swish::Layer_Elementwise::OCV/CPU_FP16        4.715           1.873               2.52
```
#### Intel i7-12700K
```
Geometric mean (ms)
            Name of Test              activations activations.patch activations.patch
                                                                    vs
                                                               activations
                                                                (x-factor)
Celu::Layer_Elementwise::OCV/CPU        17.106       3.560         4.81
Elu::Layer_Elementwise::OCV/CPU          5.064       3.478         1.46
Gelu::Layer_Elementwise::OCV/CPU         0.036       0.035         1.04
HardSwish::Layer_Elementwise::OCV/CPU    2.914       2.893         1.01
Mish::Layer_Elementwise::OCV/CPU         3.820       3.529         1.08
Selu::Layer_Elementwise::OCV/CPU        10.799       3.593         3.01
Swish::Layer_Elementwise::OCV/CPU        3.651       3.473         1.05
```
### 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