Remove source validation from converters and interfaces

[h-mayorquin]

Should fix #1166.

Also, this problem came again with the IBL collaboration (personal communication).

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 90.07%. Comparing base (96dfdff) to head (45f64f9).
Report is 15 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1168      +/-   ##
==========================================
- Coverage   90.69%   90.07%   -0.62%     
==========================================
  Files         129      129              
  Lines        8189     8284      +95     
==========================================
+ Hits         7427     7462      +35     
- Misses        762      822      +60     

Flag	Coverage Δ
unittests	90.07% <ø> (-0.62%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
src/neuroconv/basedatainterface.py	87.05% <ø> (-8.30%)	⬇️
src/neuroconv/nwbconverter.py	87.68% <ø> (-7.29%)	⬇️

... and 15 files with indirect coverage changes