feat: allow overriding checkly base url [kit-00]#1181

miliberlin wants to merge 3 commits intomaincheckly/checkly-cli:mainfrom

michelleliebheit/sc-00/override-checkly-base-urlcheckly/checkly-cli:michelleliebheit/sc-00/override-checkly-base-urlCopy head branch name to clipboard