chore: error logging for auto material requests

[ankush]

Traceback (most recent call last):
  File "apps/frappe/frappe/core/doctype/scheduled_job_type/scheduled_job_type.py", line 85, in execute
    frappe.get_attr(self.method)()
  File "apps/erpnext/erpnext/stock/reorder_item.py", line 22, in reorder_item
    return _reorder_item()
  File "apps/erpnext/erpnext/stock/reorder_item.py", line 99, in _reorder_item
    return create_material_request(material_requests)
  File "apps/erpnext/erpnext/stock/reorder_item.py", line 222, in create_material_request
    notify_errors(exceptions_list)
  File "apps/erpnext/erpnext/stock/reorder_item.py", line 256, in notify_errors
    exception = json.loads(exception)
  File "/usr/lib/python3.7/json/__init__.py", line 348, in loads
    return _default_decoder.decode(s)
  File "/usr/lib/python3.7/json/decoder.py", line 337, in decode
    obj, end = self.raw_decode(s, idx=_w(s, 0).end())
  File "/usr/lib/python3.7/json/decoder.py", line 355, in raw_decode
    raise JSONDecodeError("Expecting value", s, err.value) from None
json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0)

If traceback is not found for some error then error reporting fails.

[codecov]

Codecov Report

Merging #31103 (7143556) into develop (a36174a) will increase coverage by 0.00%.
The diff coverage is 0.00%.

@@           Coverage Diff            @@
##           develop   #31103   +/-   ##
========================================
  Coverage    63.19%   63.19%           
========================================
  Files          986      986           
  Lines        67358    67361    +3     
========================================
+ Hits         42564    42569    +5     
+ Misses       24794    24792    -2     

Impacted Files	Coverage Δ
erpnext/stock/reorder_item.py	74.16% <0.00%> (-3.62%)	⬇️
...rial_no_valuation/incorrect_serial_no_valuation.py	85.96% <0.00%> (-10.53%)	⬇️
...rpnext/accounts/doctype/shareholder/shareholder.py	80.00% <0.00%> (-10.00%)	⬇️
...pnext/accounts/report/gross_profit/gross_profit.py	80.24% <0.00%> (-7.41%)	⬇️
...t/accounts/report/sales_register/sales_register.py	71.92% <0.00%> (-5.85%)	⬇️
...e/asset_value_adjustment/asset_value_adjustment.py	86.04% <0.00%> (-3.49%)	⬇️
erpnext/utilities/activation.py	62.85% <0.00%> (-2.86%)	⬇️
...em_wise_sales_register/item_wise_sales_register.py	61.99% <0.00%> (-0.91%)	⬇️
erpnext/stock/report/stock_ledger/stock_ledger.py	84.92% <0.00%> (-0.80%)	⬇️
... and 21 more