test: add scenario check "customize transaction nonce" toggle works correctly.

[sleepytanya]

Description

In this PR we add the scenario for the flow 'Check "Customize transaction nonce works correctly'.
This task belongs to the effort of documenting manual QA flows in this Epic.

Related issues

Fixes: 21989

Manual testing steps

1. Verify that the test steps align with the sequence in the video.
   You can find rendered table here.

Pre-merge author checklist

• I’ve followed MetaMask Coding Standards.
• I've clearly explained what problem this PR is solving and how it is solved.
• I've linked related issues
• I've included manual testing steps
• I've included screenshots/recordings if applicable
• I’ve included tests if applicable
• I’ve documented my code using JSDoc format if applicable
• I’ve applied the right labels on the PR (see labeling guidelines). Not required for external contributors.
• I’ve properly set the pull request status:
  • In case it's not yet "ready for review", I've set it to "draft".
  • In case it's "ready for review", I've changed it from "draft" to "non-draft".

Pre-merge reviewer checklist

• I've manually tested the PR (e.g. pull and build branch, run the app, test code being changed).
• I confirm that this PR addresses all acceptance criteria described in the ticket it closes and includes the necessary testing evidence such as recordings and or screenshots.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 68.72%. Comparing base (d980602) to head (dbde739).
Report is 18 commits behind head on develop.

Additional details and impacted files

@@           Coverage Diff            @@
##           develop   #23413   +/-   ##
========================================
  Coverage    68.71%   68.72%           
========================================
  Files         1105     1105           
  Lines        43250    43250           
  Branches     11562    11562           
========================================
+ Hits         29719    29720    +1     
+ Misses       13531    13530    -1     

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[github-actions]

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