Misc secret storage fixes

[poljar]

These two commits are part of #2621, I'm pulling them out to get at least some parts of that PR merged.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (71627a2) 78.78% compared to head (2366164) 78.77%.
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2757      +/-   ##
==========================================
- Coverage   78.78%   78.77%   -0.01%     
==========================================
  Files         204      204              
  Lines       20736    20736              
==========================================
- Hits        16337    16335       -2     
- Misses       4399     4401       +2     

Files	Coverage Δ
crates/matrix-sdk-crypto/src/secret_storage.rs	90.90% <100.00%> (-1.52%)	⬇️

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[bnjbvr]

Approving and merging for the sake of expediency, but would be super nice to add some regression tests when you're back, if possible, since it's absolutely not clear what this fixes.

[poljar]

Approving and merging for the sake of expediency, but would be super nice to add some regression tests when you're back, if possible, since it's absolutely not clear what this fixes.

Well I hope that a forgotten re-export is sufficiently clear. The other commit changes the event_type() method to use a Ruma type instead of a string. The event_type() method is already tested as you can see I had to change the test as well.

[bnjbvr]

I completely failed to see the second part was changing tests, my bad (and thanks!).