fix: POS runtime effect

[RitvikSardana]

Issue:

In POS whenever we return an item it is not reflected in the item quantity till we close the POS, because of this the returned item can't be used in the current POS.

Solution:
The item qty is updated as soon as it is returned.

[rtdany10]

Does it update the stock real time for all cases or only on returns?
Also there is a print statement in the code.

[RitvikSardana]

@rtdany10

the stock is updated both times
when it is sold and when it is returned

[deepeshgarg007]

@rtdany10 This is not for real-time stock updation. This is to handle the return stock item where they will be readily available to be sold again unlike earlier where they were available only after POS Closing

[codecov]

Codecov Report

Merging #36492 (0d95fc0) into develop (10529e1) will increase coverage by 0.28%.
Report is 167 commits behind head on develop.
The diff coverage is 45.63%.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop   #36492      +/-   ##
===========================================
+ Coverage    64.54%   64.83%   +0.28%     
===========================================
  Files          787      792       +5     
  Lines        61176    61800     +624     
===========================================
+ Hits         39486    40065     +579     
- Misses       21690    21735      +45     

Files Changed	Coverage Δ
...rpnext/accounts/doctype/pos_invoice/pos_invoice.py	73.27% <ø> (ø)
...ype/pos_invoice_merge_log/pos_invoice_merge_log.py	79.80% <ø> (ø)
...counts/report/accounts_payable/accounts_payable.py	100.00% <ø> (ø)
...counts_payable_summary/accounts_payable_summary.py	0.00% <ø> (ø)
..._receivable_summary/accounts_receivable_summary.py	0.00% <0.00%> (ø)
...counts/report/financial_ratios/financial_ratios.py	0.00% <0.00%> (ø)
erpnext/crm/doctype/lead/lead.py	68.03% <ø> (ø)
erpnext/accounts/party.py	77.40% <18.18%> (-0.76%)	⬇️
erpnext/accounts/doctype/account/account.py	73.18% <57.14%> (-0.42%)	⬇️
.../report/accounts_receivable/accounts_receivable.py	71.11% <58.18%> (-1.56%)	⬇️
... and 11 more

... and 34 files with indirect coverage changes