New Issue: I/O: deprecate binary conversions in format strings

18503, "jhh67", "I/O: deprecate binary conversions in format strings ", "2021-09-30T22:50:43Z"

Chapel format strings currently allow writing arguments in binary. This adds to the excessive complexity of the format strings. This format string functionality should be deprecated and replaced with channel methods that implement the same functionality, e.g. writeBigEndian().