feat: early payment discount on sales & purchase orders

[nextchamp-saqib]

#28931 only enables "Invoices" for early payment discounts
Sales Orders & Purchase Orders with Payment Terms should also be eligible for early payment discounts

no-docs

[codecov]

Codecov Report

Merging #29101 (867fe5a) into develop (c620836) will increase coverage by 0.04%.
The diff coverage is 100.00%.

@@             Coverage Diff             @@
##           develop   #29101      +/-   ##
===========================================
+ Coverage    57.89%   57.93%   +0.04%     
===========================================
  Files         1110     1110              
  Lines        67993    67990       -3     
===========================================
+ Hits         39364    39390      +26     
+ Misses       28629    28600      -29     

Impacted Files	Coverage Δ
...xt/accounts/doctype/payment_entry/payment_entry.py	69.39% <100.00%> (+0.05%)	⬆️
...work_order_stock_report/work_order_stock_report.py	50.00% <0.00%> (-50.00%)	⬇️
...em_wise_sales_register/item_wise_sales_register.py	51.81% <0.00%> (-9.55%)	⬇️
...unts/report/purchase_register/purchase_register.py	73.28% <0.00%> (-4.80%)	⬇️
...e/asset_value_adjustment/asset_value_adjustment.py	86.04% <0.00%> (-3.49%)	⬇️
...e_purchase_register/item_wise_purchase_register.py	75.00% <0.00%> (-3.00%)	⬇️
...eport/production_analytics/production_analytics.py	69.51% <0.00%> (-1.22%)	⬇️
erpnext/support/doctype/issue/issue.py	64.56% <0.00%> (-0.98%)	⬇️
.../report/accounts_receivable/accounts_receivable.py	71.79% <0.00%> (-0.86%)	⬇️
erpnext/selling/doctype/quotation/quotation.py	49.18% <0.00%> (-0.55%)	⬇️
... and 28 more