ccv: rename error type enumerators

ccv: rename error type enumerators

In the names of enumerators:

 - Replace "other" with "unknown" when referring to origins in clock
   correlation validator error types.

   The origin of a clock class is either known or unknown.  As of MIP 0,
   the only way for a clock class origin to be known is for it to be the
   Unix epoch, so it's really either Unix epoch or unknown.

   With MIP 1, it will become possible to have known origins that are
   not the Unix epoch.  Using the term "unknown" here makes it clear
   that we are not talking about that.

 - Replace "origin uuid" with "origin unknown with uuid", "origin no
   uuid" with "origin unknown without uuid".  The formers make it sound
   like the origins have UUIDs, which is not the case.  The clock class
   (which is implied in the name) has a UUID.

 - Make the enumerators extra explicit to avoid any ambiguity.

Change-Id: I4e9f9e6caf4e09de2ff1a2d26fe10a1a5f343453
Signed-off-by: Simon Marchi <simon.marchi@efficios.com>
Reviewed-on: https://review.lttng.org/c/babeltrace/+/12783
Reviewed-by: Philippe Proulx <eeppeliteloop@gmail.com>
Tested-by: jenkins <jenkins@lttng.org>