[swift] fix broken swift test build (#7633) (#7634)

* [swift] fix broken swift test build (#7633)

* [swift] fix unused variable (#7633)

* [swift] update generated code (#7633)

* [swift] add binary & json test for nan, inf, -inf for swift (#7633)

* [swift] use just '.infinity' instead of '+.infinity' (#7633)

* [swift] remove commented code (#7633)

Co-authored-by: Derek Bailey <derekbailey@google.com>
Co-authored-by: mustiikhalil <26250654+mustiikhalil@users.noreply.github.com>