STYLE: reorder global funcs and opers in Tensor types

  - In the course of time, global funcs/opers of Tensor types expanded
    leaving funcs/opers unordered.

  - Therefore, by following the order designated in Matrix class, the order
    of global funcs and global opers are reordered:
    - oper+ oper- oper* oper/ inner-product double-inner-product outer-product