Update Define Joint operator

[AlpenAalAlex]

Description

• Add feedback to operator
• Forget last joint's name

Related Issue

#350

Motivation and Context

How Has This Been Tested?

Changed class is not used in other areas of the code. Intended effects achieved

Screenshots (if appropriate):

Types of changes

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

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.