deprecating fnum-based operations in VDH

[keighrim]

fixing #379

[codecov]

Codecov Report

❌ Patch coverage is 80.00000% with 23 lines in your changes missing coverage. Please review.
✅ Project coverage is 73.62%. Comparing base (d918869) to head (968c3dd).
⚠️ Report is 4 commits behind head on develop.

Files with missing lines	Patch %	Lines
mmif/utils/video_document_helper.py	80.00%	23 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop     #382      +/-   ##
===========================================
+ Coverage    73.27%   73.62%   +0.34%     
===========================================
  Files           27       27              
  Lines         3121     3204      +83     
===========================================
+ Hits          2287     2359      +72     
- Misses         834      845      +11     

Flag	Coverage Δ
unittests	73.62% <80.00%> (+0.34%)	⬆️

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

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.