feat: break out message stores into their own crates

[davidsteiner]

No description provided.

[codecov]

Codecov Report

❌ Patch coverage is 96.34146% with 12 lines in your changes missing coverage. Please review.
✅ Project coverage is 89.66%. Comparing base (ed169a1) to head (5252ebb).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
crates/hotfix-store/src/file.rs	65.71%	12 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #290      +/-   ##
==========================================
+ Coverage   89.42%   89.66%   +0.24%     
==========================================
  Files          83       84       +1     
  Lines        8072     8376     +304     
==========================================
+ Hits         7218     7510     +292     
- Misses        854      866      +12     

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