[nim] #X Cleaning up
[nim] #8 Renames 'distribution plan line item' to 'distribution plan node'. Preparing for tree-like storage
"[nim] #8  'distribution plan line item' should remain. "

This reverts commit fdfe7cbd45d003b6bfcfdb17309b4cdd0cedb80a.
[nim] #X Cleans up residual tables