fix(core-transactions): throw if transaction key is already taken

[spkjp]

Summary

Checklist

• Documentation (if necessary)
• Tests (if necessary)
• Ready to be merged

[codecov]

Codecov Report

Merging #3095 into develop will decrease coverage by <.01%.
The diff coverage is 50%.

@@             Coverage Diff             @@
##           develop    #3095      +/-   ##
===========================================
- Coverage    65.72%   65.71%   -0.01%     
===========================================
  Files          425      425              
  Lines        11812    11816       +4     
  Branches      1617     1618       +1     
===========================================
+ Hits          7763     7765       +2     
- Misses        4013     4015       +2     
  Partials        36       36

Impacted Files	Coverage Δ
packages/crypto/src/errors.ts	80% <50%> (-1.14%)	⬇️
packages/crypto/src/transactions/registry.ts	70.27% <50%> (-1.16%)	⬇️

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