Reimplement BIO_dump_indent() with CBS/CBB and BIO_printf()

Reimplement BIO_dump_indent() with CBS/CBB and BIO_printf()

Instead of heaps of unchecked strlcpy/strlcat/snprintf doing hard to follow
gymnastics, use a byte string, a somewhat comprehensible computation of the
number of bytes to dump per output line and write using checked BIO_printf()
directly to the BIO.

Longer strings will still overflow the terminal width of 80 and even longer
strings will still overflow the return value (undefined behavior). I don't
care much about the former but the latter should be fixed in a later pass.

ok beck