Merge pull request #23161 from dkurt:dnn_tflite

TFLite models importer

* initial commit

* Refactor TFLiteImporter

* Better FlatBuffers detection

* Add permute before 4D->3D reshape

* Track layers layout

* TFLite Convolution2DTransposeBias layer

* Skip TFLite tests without FlatBuffers

* Fix check of FlatBuffers in tests. Add readNetFromTFLite from buffer

* TFLite Max Unpooling test

* Add skip for TFLite unpooling test

* Revert DW convolution workaround

* Fix ObjC bindings

* Better errors handling

* Regenerate TFLite schema using flatc

* dnn(tflite): more checks, better logging

* Checks for unimplemented fusion. Fix tests

cmake/OpenCVFindFlatBuffers.cmake

@@ -0,0 +1,15 @@
+set(HAVE_FLATBUFFERS FALSE)
+
+if(NOT WITH_FLATBUFFERS)
+  return()
+endif()
+
+list(APPEND CUSTOM_STATUS flatbuffers)
+
+find_package(flatbuffers QUIET)
+if(flatbuffers_FOUND)
+  set(HAVE_FLATBUFFERS 1)
+  list(APPEND CUSTOM_STATUS_flatbuffers "    FlatBuffers:" "${flatbuffers_VERSION}")
+else()
+  list(APPEND CUSTOM_STATUS_flatbuffers "    FlatBuffers:" "NO")
+endif()