[upd] Tensor interface

Context

Apply #292 recommendations

Major modifications

• upd: Tensor getters and boolean query names and make other functions deprecated
  • getImpl() => impl()
  • getImplOffset() => implOffset()
  • dataType() => dtype()
  • dataFormat() => dformat()
  • stride(idx) => X
  • dim(idx) => X
  • undefined() => isUndefined()
  • empty() => isEmpty()
  • hasImpl() => X
  • setDataType() => toDtype()
  • setDataFormat() => toDformat()
  • setBackend() => toBackend()
  • toCoord() => asCoord() // to keep toX for setters that do more computation than setting a variable
  • toIdx() => asIdx()
  • getStorageIdx() => storageIdx()
• upd: change Tensor Python binding getters to properties (e.g my_tensor.grad => refer to grad() and setGrad())
  • dtype() => dtype
  • dformat() => dformat
  • dims() => dims
  • size() => size
  • capacity() => capacity
  • strides() => strides
  • impl() => impl