Cannot +-*/ for diagonal and non-diagonal UniTensor

[hunghaoti]

As title, it will throw the error says that the rank not match

The related unit tests are: https://github.com/Cytnx-dev/Cytnx/blob/f62f0cedd6197f7c68999dd2f814783c4b40cc8e/tests/DenseUniTensor_test.cpp#L2010 https://github.com/Cytnx-dev/Cytnx/blob/f62f0cedd6197f7c68999dd2f814783c4b40cc8e/tests/DenseUniTensor_test.cpp#L2206 https://github.com/Cytnx-dev/Cytnx/blob/f62f0cedd6197f7c68999dd2f814783c4b40cc8e/tests/DenseUniTensor_test.cpp#L2470 https://github.com/Cytnx-dev/Cytnx/blob/f62f0cedd6197f7c68999dd2f814783c4b40cc8e/tests/DenseUniTensor_test.cpp#L2670 https://github.com/Cytnx-dev/Cytnx/blob/f62f0cedd6197f7c68999dd2f814783c4b40cc8e/tests/DenseUniTensor_test.cpp#L2933 https://github.com/Cytnx-dev/Cytnx/blob/f62f0cedd6197f7c68999dd2f814783c4b40cc8e/tests/DenseUniTensor_test.cpp#L3132 https://github.com/Cytnx-dev/Cytnx/blob/f62f0cedd6197f7c68999dd2f814783c4b40cc8e/tests/DenseUniTensor_test.cpp#L3397 https://github.com/Cytnx-dev/Cytnx/blob/f62f0cedd6197f7c68999dd2f814783c4b40cc8e/tests/DenseUniTensor_test.cpp#L3594