Fragment handling decreasing performance for large number of cmHandles

- allow fragmentEntity to set parent id (needed for optimization)
- updated addListAlement and addChildDataNode to use new common optimized metghod to add to exsiting children
- ensure methods are transactional
- Refactored test around adding list elements to clearly define test
  checking the presence of grandchild element

Issue-ID: CPS-886
Change-Id: Ic4381f0f7170ebd666d5bc8aa6ef2c4548d81766
Signed-off-by: DylanB95EST <dylan.byrne@est.tech>