Allow user to change its password

[sparshev]

The change allows admin and user himself to change password when needed. Admin can change the other users passwords and user can change it's own password now. Before admin was able to recreate user, but for admin there was no way to change auto-generated password.

Motivation and Context

Needed for smooth migration

How Has This Been Tested?

Manually

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• [x] I have signed the Adobe Open Source CLA.
• [x] My code follows the code style of this project.
• [ ] My change requires a change to the documentation.
• [ ] I have updated the documentation accordingly.
• [x] I have read the CONTRIBUTING document.
• [ ] I have added tests to cover my changes.
• [x] All new and existing tests passed.