CLEANUP: ssl/cli: use a local context for "set ssl crlfile"

CLEANUP: ssl/cli: use a local context for "set ssl crlfile"

Just like for "set ssl cafile", the command doesn't really need this
context which doesn't outlive the parsing function but it was there
for a purpose so it's maintained. Only 3 fields were used from the
appctx's ssl context: old_crlfile_entry, new_crlfile_entry, and path.
These ones were reinstantiated into a new "set_crlfile_ctx" struct.
It could have been merged with the one used in "set cafile" if the
fields had been renamed since cafile and crlfile are of the same
type (probably one of them ought to be renamed?).

None of these fields could be dropped as they are still shared with
other commands.