Remove deprecated Request->getMethod($upper)

Team, I would like to send a PR to delete @deprecated. 

Github OutgoingRequest

But this will cause errors in the CLI tests, CURL.. Because since ancient times, methods could be uppercase/lowercase. Now 99% of methods have capital letters (POST, GET,..) Should I delete such mentions and tests? Or is there another option?
Plus I saw that routing also relies on get/post writing. It would be worth fixing this as well

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