Test malleability attacks (backport #3925)

[mergify]

Describe your changes

• Adds property tests for malleability attacks on transactions
• Improves test_wrapper_unknown_address
• Removes old references to encrypted/decrypted txs

Checklist before merging

• If this PR has some consensus breaking changes, I added the corresponding breaking:: labels
  • This will require 2 reviewers to approve the changes
• If this PR requires changes to the docs or specs, a corresponding PR is opened in the namada-docs repo
  • Relevant PR if applies:
• If this PR affects services such as namada-indexer or namada-masp-indexer, a corresponding PR is opened in that repo
  • Relevant PR if applies:

---

This is an automatic backport of pull request #3925 done by [Mergify](https://mergify.com).

[codecov]

Codecov Report

Attention: Patch coverage is 95.55556% with 6 lines in your changes missing coverage. Please review.

Project coverage is 74.04%. Comparing base (430a97c) to head (55bca4d).
Report is 11 commits behind head on maint-0.45.

Files with missing lines	Patch %	Lines
crates/node/src/shell/process_proposal.rs	88.23%	6 Missing ⚠️

Additional details and impacted files

@@              Coverage Diff               @@
##           maint-0.45    #4038      +/-   ##
==============================================
+ Coverage       73.88%   74.04%   +0.16%     
==============================================
  Files             341      341              
  Lines          106494   106561      +67     
==============================================
+ Hits            78684    78907     +223     
+ Misses          27810    27654     -156     

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