Revert "ECMS-5764: Slowness in UIJCRExplorerPortlet.processRender within ECMS Read document context"

This reverts commit 19fdcb27a4c1961d298287a88ab6936c7e64dc3a.
ECMS-5635: [Performance][Content Explorer] Slowness in showDocument

Fix description:
 -  paginate the child nodes inside current node using QueryImpl offset and limit
Merge commit '9a7cdb375a7522ac54ffbe277e4d5714ea9d4595' into HEAD