[NODE][REFLECTION] Support NDArray as field (#1452)

HalideIR

include/tvm/runtime/ndarray.h

include/tvm/runtime/serializer.h

nnvm/python/nnvm/compiler/param_dict.py

nnvm/src/compiler/graph_runtime.cc

nnvm/src/compiler/graph_runtime.h

nnvm/tests/python/compiler/test_param_dict.py

python/tvm/_ffi/_ctypes/function.py

python/tvm/_ffi/_cython/node.pxi

python/tvm/_ffi/ndarray.py

src/api/dsl_api.cc

src/common/base64.h

src/lang/reflection.cc

src/runtime/graph/graph_runtime.cc

src/runtime/graph/graph_runtime.h