cpp-common/bt2c: move `uuid-view.*pp` contents to `uuid.hpp`

cpp-common/bt2c: move `uuid-view.*pp` contents to `uuid.hpp`

The two methods in `uuid-view.cpp`, a file which wasn't even mentioned
in `src/Makefile.am`, existed to break the cycle because `bt2c::Uuid`
and `bt2c::UuidView` need to know eachother.

Instead, remove `uuid-view.cpp`, and put both `bt2c::Uuid` and
`bt2c::UuidView` in `uuid.hpp`, inlining everything and keeping the
close relationship between those two classes.

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Change-Id: Ia27de9f23aaa5e38beb446c7bafcae1fb2f17aa7
Reviewed-on: https://review.lttng.org/c/babeltrace/+/11429
Tested-by: jenkins <jenkins@lttng.org>
Reviewed-by: Simon Marchi <simon.marchi@efficios.com>
CI-Build: Simon Marchi <simon.marchi@efficios.com>