refactor: clean up product bundle client side code

[ankush]

• Remove deprecated CUR_FRM scripts
• Remove client-side fetches and move it to doctype schema.

Also resolves the issue of bulk pasting item codes and not auto-populating item info.

ref: ISS-22-23-00838

[codecov]

Codecov Report

Merging #31455 (035ef03) into develop (173588e) will increase coverage by 0.18%.
The diff coverage is n/a.

@@             Coverage Diff             @@
##           develop   #31455      +/-   ##
===========================================
+ Coverage    63.55%   63.73%   +0.18%     
===========================================
  Files          986      986              
  Lines        67854    67854              
===========================================
+ Hits         43122    43245     +123     
+ Misses       24732    24609     -123     

Impacted Files	Coverage Δ
...unts/report/purchase_register/purchase_register.py	34.21% <0.00%> (-42.77%)	⬇️
...ext/accounts/report/balance_sheet/balance_sheet.py	36.36% <0.00%> (-21.82%)	⬇️
...e_purchase_register/item_wise_purchase_register.py	57.42% <0.00%> (-19.81%)	⬇️
...saction/incorrect_balance_qty_after_transaction.py	88.37% <0.00%> (-9.31%)	⬇️
...value/warehouse_wise_item_balance_age_and_value.py	89.02% <0.00%> (-2.44%)	⬇️
...eorder_level/itemwise_recommended_reorder_level.py	88.88% <0.00%> (-1.86%)	⬇️
erpnext/stock/doctype/item_price/item_price.py	92.98% <0.00%> (-1.76%)	⬇️
erpnext/stock/reorder_item.py	73.33% <0.00%> (-1.67%)	⬇️
erpnext/portal/utils.py	27.69% <0.00%> (-1.54%)	⬇️
erpnext/crm/doctype/prospect/prospect.py	49.25% <0.00%> (-1.50%)	⬇️
... and 30 more