fix: correction of the calculation to the average value when there is…

[HarryPaulo]

Short Problema correction: Correction of the calculation to the average value when there is a discount on the document and not on the items

Authorization rule configuration:

Profile 1: Seller up to 10%:
-> Transaction: Sales Order
-> based_on: Average Discount

Profile 2: Manager up to 15%
-> Transaction: Sales Order
-> based_on: Average Discount

Problem:
When making a sale with the following characteristics:
Item: ITEM A
Qty: 2
Value: $100
Price List Rate: $100

Total Items: $200
discount_amount: $20 (on document)

Total with discount: $180
Discount represents 10% of the sale in this situation.

With the code before my change, this example above is returning 20% ​​off average (av_dis)

price_list_rate = 100
base_rate = 100
base_rate = 100 - 20 = 80

Formula: 100 - flt(base_rate * 100 / price_list_rate)
av_dis = 100 - flt(80 * 100 / 100)
av_dis = 20 % "Wrong percentage"

-> With my change Makes the calculation based on the total value of the sale, as the discount on the document is based on the total of the items:
price_list_rate = 100 * 2
base_rate = 100 * 2
base_rate = 200 - 20 = 180

Formula: av_dis = 100 - flt(base_rate * 100 / price_list_rate)
av_dis = 100 - flt(180 * 100 / 200)
av_dis = 10 % "Percent Correct"

[codecov]

Codecov Report

Merging #31016 (d0a9eb4) into develop (e3c0d01) will increase coverage by 0.29%.
The diff coverage is 0.00%.

@@             Coverage Diff             @@
##           develop   #31016      +/-   ##
===========================================
+ Coverage    62.97%   63.26%   +0.29%     
===========================================
  Files          986      986              
  Lines        67417    67417              
===========================================
+ Hits         42453    42651     +198     
+ Misses       24964    24766     -198     

Impacted Files	Coverage Δ
...ype/authorization_control/authorization_control.py	10.15% <0.00%> (ø)
...tch_item_expiry_status/batch_item_expiry_status.py	67.92% <0.00%> (-24.53%)	⬇️
...wise_balance_history/batch_wise_balance_history.py	67.79% <0.00%> (-22.04%)	⬇️
...rpnext/accounts/doctype/shareholder/shareholder.py	80.00% <0.00%> (-10.00%)	⬇️
...saction/incorrect_balance_qty_after_transaction.py	88.37% <0.00%> (-9.31%)	⬇️
.../report/bom_operations_time/bom_operations_time.py	89.13% <0.00%> (-2.18%)	⬇️
.../fifo_queue_vs_qty_after_transaction_comparison.py	93.10% <0.00%> (-1.73%)	⬇️
...pnext/accounts/report/gross_profit/gross_profit.py	80.24% <0.00%> (-1.65%)	⬇️
erpnext/stock/get_item_details.py	80.44% <0.00%> (-0.15%)	⬇️
...stock/doctype/purchase_receipt/purchase_receipt.py	92.19% <0.00%> (ø)
... and 27 more