Set unit settings to undefined on clear unit type 6.1

[maxiadlovskii]

Note: This is a backport of #21399 to 6.1

Description

This PR set unit settings to undefined on clear unit type. In this case instead of empty object we send undefined to BE and that fix an issue

Motivation and Context

fix: #21398

How Has This Been Tested?

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Refactoring (non-breaking change)
• 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.
• I have added tests to cover my changes.