Add Ledger app unit tests to the Namada CI (backport #4140)

[mergify]

Describe your changes

An attempt to add Ledger app unit tests to the Namada CI. These tests were created to complement the Ledger app E2E tests already in the CI at test-e2e-with-device-automation. Whereas the E2E tests comprehensively cover testing hardware wallet signing for a few cases, these unit tests focus on covering hardware wallet printing for hundreds of cases. More specifically, the following changes have been made:

• Made the CI automatically generate random transaction test vectors using the Namada client
  • Doing this has the side benefit of preventing code rot in the test vector generation code
• The CI then runs the Ledger app unit test code on the generated test vectors
  • Doing this helps automatically detect compatibility breaking changes in the transaction serializations
• Fixed regressions in the test vector generation code

See an example run of this new job here: https://github.com/murisi/namada/actions/runs/12143664343/job/33861086521?pr=2

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 #4140 done by [Mergify](https://mergify.com).

[codecov]

Codecov Report

Attention: Patch coverage is 1.78571% with 55 lines in your changes missing coverage. Please review.

Project coverage is 74.53%. Comparing base (8a15225) to head (ab6b4a6).
Report is 7 commits behind head on maint-libs-0.46.

Files with missing lines	Patch %	Lines
crates/sdk/src/signing.rs	0.00%	55 Missing ⚠️

Additional details and impacted files

@@                 Coverage Diff                 @@
##           maint-libs-0.46    #4162      +/-   ##
===================================================
- Coverage            74.58%   74.53%   -0.05%     
===================================================
  Files                  341      341              
  Lines               107499   107546      +47     
===================================================
- Hits                 80180    80164      -16     
- Misses               27319    27382      +63     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.