SubSample Image Loading

[BryonLewis]

resolves #1329

Done:

• Frame remapping when images are a subsample of those referenced in a loaded CSV file for electron
• Updated client tests for new errors and formats
• If images referenced in CSV include images in the dataset and they are in the proper order it will allow loading
• Extra images are ignored then
• Logic for this has been updated on Electron version as well as python version

Testing:

• Take a sample dataset like Ehu from the server and copy and create 3 different folders. Ehu Link
  • The base dataset with all the images
  • A subsampled dataset with 20-30 sequential images
  • A subsampled dataset with 20-30 non-sequential images
• Take the original annotations.csv file from Ehu and load it into the sequential images dataset. It should load and display annotations properly. The frame numbers will be different but it should load
• Attempt to load the original into the non-sequential image dataset and an error should occur.
• You can take a look at the viame.spec.ts file for the client version and the test_serialize_viame_csv.py for the python version and create some other sample CSVs and check that they import properly and give the proper errors.

[marySalvi]

LGTM. Followed the testing steps provided and everything worked as expected. This is very cool btw.