Replace libuuid with internal implementation

Replace libuuid with internal implementation

We use a very small subset of libuuid features to transform UUIDs
between their string and binary representation. Plus we have a lot of
compat code for different platforms with some unspecified default
behavior regarding the use of upper/lower case.

Drop the dependency on libuuid and replace it with a minimal internal
implementation that respects RFC4122.

Change-Id: Ic170ce26ade23d177195cad117bd0fab590b328e
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Reviewed-on: https://review.lttng.org/c/babeltrace/+/1572
Tested-by: jenkins <jenkins@lttng.org>
Reviewed-by: Philippe Proulx <eeppeliteloop@gmail.com>