Add tests for Scalar and Inverval values for UnaryMinus

[kazuyukitanimura]

Describe the bug

Related to #471, we should add tests for Scalar and Inverval values for UnaryMinus

Steps to reproduce

No response

Expected behavior

No response

Additional context

No response

[vaibhawvipul]

I will work on this.

[kazuyukitanimura]

Thank you @vaibhawvipul assigned this to you

[vaibhawvipul]

@kazuyukitanimura I have added scalar tests, and I have also verified that it hits scalar path in the negative.rs code. Please review when you get a chance.