Add testing coverage for button_to in ButtonComponent

What does this MR do and why?

Add testing coverage for button_to in ButtonComponent

• add test coverage.
• resolve rubocop exceptions.
• document expected behavior that happens when supplying options to button_to as per https://api.rubyonrails.org/classes/ActionView/Helpers/UrlHelper.html#method-i-button_to
• see #439209 (closed)

MR acceptance checklist

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Related to #482908