Implemente undergo_nmd method

[gromdimon]

Issue:

• Closes Implement _undergo_nmd method for StrucVars #47

Description:

• Implemented method
• Added additional check for deletions (at least affect one full exon)
• Added Unit tests

[codecov]

Codecov Report

Attention: Patch coverage is 80.00000% with 7 lines in your changes missing coverage. Please review.

Project coverage is 84.00%. Comparing base (fdcaa9a) to head (ef0e0a3).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
src/strucvar/auto_pvs1.py	80.00%	7 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #190      +/-   ##
==========================================
- Coverage   84.35%   84.00%   -0.35%     
==========================================
  Files          65       65              
  Lines        4678     4708      +30     
==========================================
+ Hits         3946     3955       +9     
- Misses        732      753      +21     

Files with missing lines	Coverage Δ
src/seqvar/auto_pvs1.py	62.76% <ø> (ø)
src/strucvar/auto_pvs1.py	55.35% <80.00%> (-5.52%)	⬇️