feat: Add option `logLevels.signupUsernameTaken` to change log level of username already exists sign-up rejection#9962

mtrezza merged 9 commits intoparse-community:alphaparse-community/parse-server:alphafrom

coratgerl:add-option-silent-user-already-existscoratgerl/parse-server:add-option-silent-user-already-existsCopy head branch name to clipboard