Rewrite nexus unpack plugin ITs using the new IT support classes

Signed-off-by: Alin Dreghiciu <adreghiciu@gmail.com>
Drop obsolete nexus unpack plugin ITs/IT resources (ITs rewrites using the new IT support classes)

Signed-off-by: Alin Dreghiciu <adreghiciu@gmail.com>
Merge remote-tracking branch 'origin/master' into unpack-plugin-its
Re-enabled UT that was disabled and fixed it.

JD disabled this UT
https://github.com/sonatype/nexus-oss/commit/46662af44f869a17f0c30becb61ad55949ecaedb

But it turns out that everything was here actually,
no baggage needed from test-jar, but only some
annotations were missing on _already copy pasted_
mock user manager.
Fix for 4439f6216b34723bbd665aa1a1db413e3089c6f2

Another test enumerated present UserManagers
present in system. Just added the most one too,
as it does not change this UT semantic at all.
Fix unpack plugin testsuite package name

Signed-off-by: Alin Dreghiciu <adreghiciu@gmail.com>
Move unpack plugin IT resources under "org.sonatype.nexus.unpack.testsuite" package

Signed-off-by: Alin Dreghiciu <adreghiciu@gmail.com>
Merge unpack plugin ITs into nexus-core-testsuite module

Signed-off-by: Alin Dreghiciu <adreghiciu@gmail.com>
Merge pull request #3 from sonatype/unpack-plugin-its

Rewrite nexus unpack plugin ITs using the new IT support classes
Merge remote-tracking branch 'origin/master' into nexus-5526-client-auth