Matrix multiplicative factor (z + z == 2 * z) (Qiskit/qiskit-aqua#1111)
Matrix multiplicative factor (z + z == 2 * z) (Qiskit/qiskit-aqua#1111)

* Matrix multiplicative factor (z + z == 2 * z)

* Adding ParameterExpression coefficients handling in MatrixOp comparison

* MatrixOp comparison: unit test for different coefficient types

* MatrixOp additions aggregation case

Co-authored-by: Steve Wood <df319c8b10182f101be29ecf0d4d148dec6c4bfc@users.noreply.github.com>
Co-authored-by: Julien Gacon <761ea7b8820f9c490794378c10a95bac00fe088d@googlemail.com>
QISKit/qiskit-sdk-py,QISKit/qiskit-sdk-py,QISKit/qiskit-sdk-py