Fixes the problem of resuming LEL images

[markccchiang]

Description

• What is implemented or fixed? Mention the linked issue(s), if any. Fixes the problem of resuming LEL images, #1226.

• How does this PR solve the issue? Give a brief summary. Modifies the protobuf message for resuming images. Adds a new bool variable used to determine whether it is an LEL image when re-opening it.

• Are there any companion PRs (frontend, protobuf)? Yes. It accompanies the frontend PR and protobuf PR.

• Is there anything else that testers should know (e.g. exactly how to reproduce the issue)? The ICD tests for opening images may need to be modified.

Checklist

• [x] changelog updated ~/ no changelog update needed~
• [x] e2e test passing / ~added corresponding fix~
• [x] protobuf updated to the latest dev commit ~/ no protobuf update needed~
• [ ] added reviewers and assignee
• [ ] added ZenHub estimate, milestone, and release

[kswang1029]

initial test looks good. please proceed with a formal PR

[github-actions[bot]]

Package	Line Rate	Health
src.Cache	66%	➖
src.DataStream	52%	➖
src.FileList	67%	➖
src.Frame	50%	➖
src.HttpServer	43%	➖
src.ImageData	28%	❌
src.ImageFitter	89%	✔
src.ImageGenerators	44%	➖
src.ImageStats	76%	✔
src.Logger	44%	➖
src.Main	54%	➖
src.Region	18%	❌
src.Session	29%	❌
src.Table	52%	➖
src.ThreadingManager	87%	✔
src.Timer	85%	✔
src.Util	49%	➖
Summary	38% (6902 / 18257)	❌