[export_cpp] dev CI is broken due to MaxPool changes

The changes impacted multiple test:

test_examples.py: Are failling due to the introduction of change in MaxPool for two reasons, the nb of outputs is not well handled and it creates an issue with the memory buffer:

Compilation log for resnet:

E         g++  -O2 -Wall -Wextra -MMD -fopenmp -I. -I./dnn -I./dnn/include -I./dnn/layers -I./dnn/parameters -c dnn/src/forward.cpp -o build/./dnn/src/forward.o 
E         dnn/src/forward.cpp: In function ‘void model_forward(const int8_t*, int8_t**, int64_t**, int8_t**)’:
E         dnn/src/forward.cpp:144:14: warning: array subscript 8028160 is outside array bounds of ‘int8_t [1204224]’ {aka ‘signed char [1204224]’} [-Warray-bounds=]
E           144 |     int64_t* _1_PadMaxPool_0_output_1 = (int64_t*) mem + _1_PADMAXPOOL_0_OUTPUT_1_OFFSET;
E               |              ^~~~~~~~~~~~~~~~~~~~~~~~
E         dnn/src/forward.cpp:100:15: note: at offset 8028160 into object ‘mem’ of size 1204224
E           100 | static int8_t mem[1204224];
E               |               ^~~
E         g++  -O2 -Wall -Wextra -MMD -fopenmp -I. -I./dnn -I./dnn/include -I./dnn/layers -I./dnn/parameters -c main.cpp -o build/./main.o 
E         main.cpp: In function ‘int main()’:
E         main.cpp:16:18: error: too few arguments to function ‘void model_forward(const int8_t*, int8_t**, int64_t**, int8_t**)’
E            16 |     model_forward(_0_PadConvAct_0_input_0, &_35_QFC_0_output_0, &_1_PadMaxPool_0_output_1);
E               |     ~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
E         In file included from main.cpp:3:
E         ./dnn/include/forward.hpp:9:6: note: declared here
E             9 | void model_forward (const int8_t* _0_PadConvAct_0_input_0,
E               |      ^~~~~~~~~~~~~
E         make: *** [Makefile:23: build/./main.o] Error 1

maxpooling test is failling too (runnable with pytest -k test_max_pooling -s), chances are that with the introduction of a new output the script compare output is not working well