Both parse/write implementations are based on mov/movenc.

This only adds support for the "Dolby Vision configuration box".
Other configuration boxes, such as
"Dolby Vision enhancement layer configuration box" are not supported.

The new functions will be used to implement parsing/writing the DOVI config
for Matroska, as well as to refactor both mov/movenc to use dovi_isom functions.
Signed-off-by: quietvoid <tcChlisop0@gmail.com>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>