Merge pull request #24294 from alexlyulkov:al/remove-torch7-from-dnn

Remove torch (old torch7) from dnn in 5.x #24294

Merge with https://github.com/opencv/opencv_extra/pull/1097

Completely removed torch (old torch7) from dnn:
- removed modules/dnn/src/torch directory that contained torch7 model parser
- removed readNetFromTorch() and readTorchBlob() public functions
- removed torch7 references from comments and help texts
- replaced links to t7 models by links to similar onnx models in js_style_transfer turtorial (similar to https://github.com/opencv/opencv/pull/24245/files)

platforms/js/opencv_js.config.py

@@ -148,7 +148,7 @@ video = {
 }
 
 dnn = {'dnn_Net': ['setInput', 'forward', 'setPreferableBackend'],
-       '': ['readNetFromCaffe', 'readNetFromTensorflow', 'readNetFromTorch', 'readNetFromDarknet',
+       '': ['readNetFromCaffe', 'readNetFromTensorflow', 'readNetFromDarknet',
             'readNetFromONNX', 'readNetFromTFLite', 'readNet', 'blobFromImage']}
 
 features2d = {'Feature2D': ['detect', 'compute', 'detectAndCompute', 'descriptorSize', 'descriptorType', 'defaultNorm', 'empty', 'getDefaultName'],