report: allow test runners to inject arbitrary values

report: allow test runners to inject arbitrary values

Per Ted's request, add to the test section reporting code the ability
for test runners to point to a file containing colon-separated key value
pairs.  These key value pairs will be recorded in the report file as
extra properties.

Requested-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Zorro Lang <zlang@redhat.com>
Signed-off-by: Zorro Lang <zlang@kernel.org>