CDM-422: Unpack refdata and write md5s / size of contents

[MrCreosote]

No description provided.

[codecov]

Codecov Report

❌ Patch coverage is 21.73913% with 36 lines in your changes missing coverage. Please review.
✅ Project coverage is 54.12%. Comparing base (3bf5e5d) to head (201a0ff).
⚠️ Report is 21 commits behind head on main.

Files with missing lines	Patch %	Lines
cdmtaskservice/refserv/refdata_manager.py	26.47%	25 Missing ⚠️
cdmtaskservice/s3/remote.py	10.00%	9 Missing ⚠️
cdmtaskservice/app_state.py	0.00%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #480      +/-   ##
==========================================
- Coverage   54.27%   54.12%   -0.16%     
==========================================
  Files          67       67              
  Lines        5446     5480      +34     
==========================================
+ Hits         2956     2966      +10     
- Misses       2490     2514      +24     

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