Add reduce functions for FDTensor

[joey12300]

PR types

New features

PR changes

APIs

Describe

1. Add 7 reduce functions for FDTensor: Max, Min, Sum, All, Any, Mean, Prod
2. Add cpp unittests for 7 reduce functions.
3. Add pull request template

Usage

FDTensor input, output;
std::vector<int> inputs = {2, 4, 3, 7, 1, 5};
input.SetExternalData({2, 3}, FDDataType::INT32, inputs.data());

// Calculate the max value for axis 0 of `inputs`
// The output result would be [[7, 4, 5]]
Max(input, &output, {0}, /* keep_dim = */true);

// Calculate the min value for axis 0 of `inputs`
// The output result would be [[2, 1, 3]]
Min(input, &output, {0}, true);

// Calculate the sum value for axis 0 of `inputs`
// The output result would be [[9, 5, 8]]
Sum(input, &output, {0}, true);

// Calculate the mean value for axis 0 of `inputs`
// The output result would be [[4, 2, 4]]
Mean(input, &output, {0}, true);

// Calculate the product value for axis 0 of `inputs`
// The output result would be [[14, 4, 15]]
Prod(input, &output, {0}, true);

std::array<bool, 6> bool_inputs = {false, false, true, true, false, true};
input.SetExternalData({2, 3}, FDDataType::BOOL, bool_inputs.data());

// Calculate the any value for axis 0 of `inputs`
// The output result would be [[true, false, true]]
Any(input, &output, {0}, true);

// Calculate the any value for axis 0 of `inputs`
// The output result would be [[false, false, true]]
All(input, &output, {0}, true);