feat: allow filing of Nil return for GSTR-1

[Sanket322]

• closes: Allow filing of Nil return for GSTR-1 #2880

_{Huly®: IC-3033}

[codecov]

Codecov Report

Attention: Patch coverage is 36.36364% with 7 lines in your changes missing coverage. Please review.

Project coverage is 60.13%. Comparing base (5f227b2) to head (b572da3).

Files with missing lines	Patch %	Lines
...st_india/doctype/gst_return_log/generate_gstr_1.py	30.00%	7 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #2906      +/-   ##
===========================================
- Coverage    60.15%   60.13%   -0.02%     
===========================================
  Files          122      122              
  Lines        12063    12066       +3     
===========================================
  Hits          7256     7256              
- Misses        4807     4810       +3     

Files with missing lines	Coverage Δ
...mpliance/gst_india/api_classes/taxpayer_returns.py	54.76% <100.00%> (ø)
...st_india/doctype/gst_return_log/generate_gstr_1.py	14.78% <30.00%> (-0.09%)	⬇️