feat: remove german CoA "SKR04 ohne Kontonummern" and rename other CoA files

[barredterra]

• Remove German CoA "SKR04 ohne Kontonummern"

  To the best of my knowledge, this is outdated, unused and not maintained.

• Consistent naming for the German CoA files we're keeping

Note: this PR makes more sense when looking at individual commits instead of the combined diff.

no-docs

[codecov]

Codecov Report

Attention: 41 lines in your changes are missing coverage. Please review.

Comparison is base (d370c60) 60.21% compared to head (5a57584) 60.20%.
Report is 27 commits behind head on develop.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop   #38805      +/-   ##
===========================================
- Coverage    60.21%   60.20%   -0.02%     
===========================================
  Files          759      759              
  Lines        69790    69855      +65     
===========================================
+ Hits         42027    42053      +26     
- Misses       27763    27802      +39     

Files	Coverage Δ
...ounts/doctype/purchase_invoice/purchase_invoice.py	70.17% <ø> (+0.05%)	⬆️
...xt/accounts/doctype/sales_invoice/sales_invoice.py	74.39% <ø> (-0.04%)	⬇️
...t/accounts/report/general_ledger/general_ledger.py	69.64% <ø> (ø)
erpnext/controllers/accounts_controller.py	85.26% <100.00%> (+0.12%)	⬆️
erpnext/controllers/selling_controller.py	79.94% <100.00%> (ø)
erpnext/setup/doctype/company/company.py	60.25% <ø> (ø)
...serial_and_batch_bundle/serial_and_batch_bundle.py	72.22% <100.00%> (+0.33%)	⬆️
...ctype/stock_reconciliation/stock_reconciliation.py	70.00% <100.00%> (-0.48%)	⬇️
erpnext/stock/stock_ledger.py	83.39% <100.00%> (+0.04%)	⬆️
erpnext/assets/doctype/asset/asset.py	73.23% <50.00%> (-0.08%)	⬇️
... and 6 more

... and 3 files with indirect coverage changes

[deepeshgarg007]

@barredterra Can you please resolve the conflicts?