Test subject externalizers in clustered mode

Verify that authorization mask is properly transferred between the node, i.e. subject externalizers work.

The test scenario could be as follows:
1. start HR server, 2. client authenticates itself to the server, 3. another server joins the cluster, 4. the first server is turned off, 5. HR client authenticate to the second server 6. verify HR client is properly authorized on second server.

Should be done for different subjects to verify different subject externalizers.