fix: incorrect default_percentage_allocation on import, binary flags imported as multivariate

[khvn26]

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Changes

This fixes two issues with LD importer:

• multivariate options created with 100% default percentage, should be 0
• standard valued features treated as multivariate with 100/0 variations

How did you test this code?

Extended unit tests.

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[codecov-commenter]

Codecov Report

All modified lines are covered by tests ✅

Comparison is base (4f7464b) 95.59% compared to head (19b29f5) 95.60%.
Report is 2 commits behind head on main.

❗ Current head 19b29f5 differs from pull request most recent head da59ae2. Consider uploading reports for the commit da59ae2 to get more accurate results

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2841   +/-   ##
=======================================
  Coverage   95.59%   95.60%           
=======================================
  Files        1009     1009           
  Lines       28833    28865   +32     
=======================================
+ Hits        27562    27595   +33     
+ Misses       1271     1270    -1     

Files	Coverage Δ
api/features/feature_types.py	100.00% <100.00%> (ø)
api/integrations/launch_darkly/services.py	100.00% <100.00%> (+0.96%)	⬆️
...s/unit/integrations/launch_darkly/test_services.py	100.00% <100.00%> (ø)

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