tests: normalize inclusions of tap/tap.h

tests: normalize inclusions of tap/tap.h

Use "tap/tap.h" instead of <tap/tap.h> everywhere.

Move the inclusion at the end of the inclusion list everywhere.  tap.h
defines macros with common names like `ok` and `fail`, which can clash
if defined before including other files.  Let's establish the practice
of including tap.h last.

Change-Id: Ic06f59d146390d6fe21a6ac229972df02ce8d762
Signed-off-by: Simon Marchi <simon.marchi@efficios.com>
Reviewed-on: https://review.lttng.org/c/babeltrace/+/11461
Tested-by: jenkins <jenkins@lttng.org>