fix: fix missing error.message in download and map share state

[gmaclennan]

error.message is non-enumerable, so the error messages were not correctly showing up in the server errors. This should fix that.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 0.00%. Comparing base (4d31316) to head (1e2e1af).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@    Coverage Diff     @@
##   main   #17   +/-   ##
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