Fixes#3211.
Adds the `--[no-]pass-through` flag which enables/disables pass-through mode.
* `zstdcat`, `zcat`, and `gzcat` default to `--pass-through`.
Pass-through mode can be disabled by passing `--no-pass-through`.
* All other binaries default to not setting pass-through mode.
However, we preserve the legacy behavior of enabling pass-through
mode when writing to stdout with `-f` set, unless pass-through
mode is explicitly disabled with `--no-pass-through`.
Adds a new test for this behavior that should codify the behavior we want.
