Add source and target refs to Pretranslations and WordAlignments

[Enkidu93]

Fixes #806

I know this won't get into the release today but I wanted to at least push my work and get the review process started since it was slated for this sprint.

There are a lot of options regarding where to keep the refs property and where to replace it (e.g., do we migrate the db?). The work currently on this branch removes the generic ref property from the machine engine side of things, but still allows old pretranslations to be properly deserialized from the bucket and keeps the refs property in the model (just adding source and target ref properties and giving them preference when utilizing them on the usfm endpoint). I've also deprecated the refs property in the dto.

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This change is 

[codecov-commenter]

Codecov Report

❌ Patch coverage is 85.61644% with 21 lines in your changes missing coverage. Please review.
✅ Project coverage is 66.53%. Comparing base (e195a31) to head (fe659b3).

Files with missing lines	Patch %	Lines
...rval.Translation/Services/PretranslationService.cs	69.04%	12 Missing and 1 partial ⚠️
...kit/Services/ParallelCorpusPreprocessingService.cs	86.48%	4 Missing and 1 partial ⚠️
...erviceToolkit/src/SIL.ServiceToolkit/Models/Row.cs	75.00%	2 Missing ⚠️
...Shared/Services/WordAlignmentPreprocessBuildJob.cs	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #863      +/-   ##
==========================================
+ Coverage   66.46%   66.53%   +0.06%     
==========================================
  Files         382      382              
  Lines       20791    20882      +91     
  Branches     2714     2714              
==========================================
+ Hits        13819    13893      +74     
- Misses       6005     6022      +17     
  Partials      967      967              

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[ddaspit]

Good job on this PR. I couldn't find any issues, which makes me a little nervous. 😁

@ddaspit reviewed 31 files and all commit messages, and made 1 comment.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @Enkidu93).

[Enkidu93]

Hahaha, thank you! I don't know whether I should take that as a compliment or not 😆, but yes - you always feel better when there's at least one change requested haha.

@Enkidu93 made 1 comment.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @Enkidu93).