WiP: Add invalid post malfeasance

[fasmat]

Motivation

Closes #6141

Description

Test Plan

TODO

• Explain motivation or link existing issue(s)
• Test changes and document test plan
• Update documentation as needed
• Update changelog as needed

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 82 lines in your changes missing coverage. Please review.

Project coverage is 81.5%. Comparing base (901b02f) to head (b64cf35).

Files with missing lines	Patch %	Lines
activation/wire/malfeasance_invalid_post.go	0.0%	82 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff            @@
##           develop   #6308     +/-   ##
=========================================
- Coverage     81.7%   81.5%   -0.3%     
=========================================
  Files          316     317      +1     
  Lines        35130   35212     +82     
=========================================
- Hits         28722   28716      -6     
- Misses        4574    4655     +81     
- Partials      1834    1841      +7     

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