Write file IDs to an identifiers.json file

[djjuhasz]

Fixes #53.

• Parse manifest datei "id" attributes
• Write the "id" values to an "identifiers.json" file in the metadata directory of the SIP
• Archivematica will add the file IDs from the identifiers.json file to the PREMIS object data in the METS file

[djjuhasz]

Here's what the dashboard record of the "write identifier file" looks like:

[djjuhasz]

And here's a sample indentifiers.json file (extracted from the downloaded AIP): identifiers.json

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 86.89655% with 19 lines in your changes missing coverage. Please review.

Project coverage is 53.82%. Comparing base (d68086a) to head (96f27d0). Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
internal/workflow/preprocessing.go	63.15%	6 Missing and 1 partial :warning:
cmd/worker/workercmd/cmd.go	0.00%	5 Missing :warning:
internal/activities/write_identifier_file.go	87.87%	2 Missing and 2 partials :warning:
internal/activities/add_premis_objects.go	81.81%	1 Missing and 1 partial :warning:
internal/activities/verify_manifest.go	91.66%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #57 +/- ## ========================================== + Coverage 51.40% 53.82% +2.41% ========================================== Files 27 30 +3 Lines 1564 1687 +123 ========================================== + Hits 804 908 +104 - Misses 696 710 +14 - Partials 64 69 +5 ```

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[djjuhasz]

I've also confirmed that the SFA file identifiers are present in the METS file: