Performance gain in Transaction Manager that was reverted from commit

[lxatstariongroup]

Prerequisites

• I have written a descriptive issue title
• I have verified that I am running the latest version of the COMET Web Services
• I have searched open and closed issues to ensure it has not already been reported

Description

(partially) reverted Commit hash: 4ccc96d
Was reverted in server version 8.0.0-RC31.
Only changes to Cdp4TransactionManager and its interface were reverted.

Reimplement reverted commit:

The solution of that commit prevents the server to retrieve data from frozen iterations. Iteration's contained properties are empty.
That should be finetuned so that also frozen iterations can be read from the server.