DEV: haring: support remapping LF in contents with CR VT

DEV: haring: support remapping LF in contents with CR VT

Some traces may contain LF characters which are quite cumbersome to
deal with using the common tools. Given that the utility still has
access to the raw traces and knows where the delimiters are, let's
offer the possibility to remap LF characters to a different sequence.

Here we're using CR VT which will have the same visual appearance but
will remain on the same line for grep etc. This behavior is enabled by
the -l option. It's not enabled by default because it's 50% slower due
to content processing.