fix: BinaryCalculator::product() rtrim usage (#174)

[will-b-tornsoft]

Fixes #174

Types of changes

What types of changes does your code introduce? Check/place an x in all the boxes that apply:

• 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)
• I have read the CONTRIBUTING document.
• 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 added tests to cover my changes.
• All new and existing tests passed.

Description

Use of rtrim($value, '0.,'), causes any value of 0 to the left of the decimal (ones-place and greater) to be trimmed off due to the way rtrim repeats removal until the first non-matching character.

Motivation and Context

Fix BinaryCalculator::product() rtrim usage (#174)

Details in my comment on the issue.

How Has This Been Tested?

Locally by running tests:

php vendor/bin/pest --colors=always