`dict_init` of KSVD class should be attribute

[sutkss]

Issue Description

scikit-learn assume that every keyword argument accepted by init should correspond to an attribute on the instance.
But, dict_init is not an attribute of KSVD class.
We need to add dict_init as an attribute of it.

References

• https://scikit-learn.org/stable/developers/develop.html

[sutkss]

Also, fixed import error in hmlasso.py