fix: Report Subcontracted Raw Materials to be Transferred

[marination]

Before:

• Over complicated logic (since there was no proper linking between PO and Stock Entry back then)
• Shows pending qty as negative on over transferring
• Also showed all Purchase Orders even if they were fully received. (nothing left to transfer)
• If multiple rows of the same raw material exist in the PO, it counts transferred qty as sum of all the rows. The key here was "Raw Material Item Code" which is incorrect in case of multiple rows with the same item code but belonging to different Finished Goods.
  

After:

• Simplified logic
• Only show information from POs that are yet to be received and have pending qty to transfer
• Inaccurate pending qty in case of same Raw Material Item Code fixed
  

Did not enhance this report too much. When #25878 gets merged, it can deprecate this report easily.