fix: include gain/loss journal in AR/AP reports

[ruthra-kumar]

Exchange Gain/Loss journal created through Exchange Rate Revaluation is not fetched on Accounts Receivable Report. This leads to outstanding amount being reported even though total debit matches total credit in ledger.

[codecov]

Codecov Report

Merging #36728 (e3104f1) into develop (8601e5b) will increase coverage by 0.11%.
Report is 32 commits behind head on develop.
The diff coverage is 89.65%.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop   #36728      +/-   ##
===========================================
+ Coverage    64.82%   64.94%   +0.11%     
===========================================
  Files          792      792              
  Lines        61798    61829      +31     
===========================================
+ Hits         40063    40157      +94     
+ Misses       21735    21672      -63     

Files Changed	Coverage Δ
...ype/pos_invoice_merge_log/pos_invoice_merge_log.py	79.80% <ø> (ø)
.../report/accounts_receivable/accounts_receivable.py	71.11% <ø> (ø)
erpnext/accounts/utils.py	73.98% <ø> (ø)
...xt/accounts/doctype/payment_entry/payment_entry.py	83.50% <87.50%> (-0.22%)	⬇️
...rpnext/accounts/doctype/pos_invoice/pos_invoice.py	73.37% <100.00%> (+0.09%)	⬆️
...serial_and_batch_bundle/serial_and_batch_bundle.py	71.15% <100.00%> (-0.06%)	⬇️

... and 8 files with indirect coverage changes