fix(minor): Filters and validations in Tax Withholding Category

[deepeshgarg007]

Duplicate accounts were allowed to be added in Tax Withholding Category, added validation for that

[codecov]

Codecov Report

Merging #28054 (7733afc) into develop (2849297) will decrease coverage by 0.03%.
The diff coverage is 85.71%.

@@             Coverage Diff             @@
##           develop   #28054      +/-   ##
===========================================
- Coverage    55.19%   55.15%   -0.04%     
===========================================
  Files         1255     1255              
  Lines        67871    67878       +7     
===========================================
- Hits         37460    37437      -23     
- Misses       30411    30441      +30     

Impacted Files	Coverage Δ
...x_withholding_category/tax_withholding_category.py	85.78% <85.71%> (-0.01%)	⬇️
...work_order_stock_report/work_order_stock_report.py	51.42% <0.00%> (-48.58%)	⬇️
...e/asset_value_adjustment/asset_value_adjustment.py	87.80% <0.00%> (-3.66%)	⬇️
erpnext/stock/report/stock_ledger/stock_ledger.py	77.50% <0.00%> (-3.34%)	⬇️
...xt/stock/report/stock_analytics/stock_analytics.py	91.08% <0.00%> (-2.98%)	⬇️
erpnext/stock/report/stock_ageing/stock_ageing.py	88.48% <0.00%> (-2.88%)	⬇️
...value/warehouse_wise_item_balance_age_and_value.py	92.59% <0.00%> (-2.47%)	⬇️
.../hr/doctype/upload_attendance/upload_attendance.py	45.11% <0.00%> (-1.51%)	⬇️
...eport/production_analytics/production_analytics.py	69.87% <0.00%> (-1.21%)	⬇️
...rpnext/stock/report/stock_balance/stock_balance.py	78.82% <0.00%> (-0.59%)	⬇️
... and 14 more