test_nfs4_acls: Add test for mapping permissions from DACL to NFS4 ACL

test_nfs4_acls: Add test for mapping permissions from DACL to NFS4 ACL

Add testcase for mapping the permission flags from the DACL in the
Security Descriptor to a NFSv4 ACL. The mapping is straight-forward as
the same permission bits exist for Security Descriptors and NFSv4 ACLs.
In addition, the code also maps from the generic DACL permissions to a
set of NFSv4 permissions, also verify this mapping.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=14032

Signed-off-by: Christof Schmitt <cs@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>