[PM-31360] Remove Reversion Related Code

[sbrown-livefront]

🎟️ Tracking

https://bitwarden.atlassian.net/browse/PM-31360

📔 Objective

This PR removes subscription and tests related to reversion of premium to organization upgrades.

⏰ Reminders before review

• Contributor guidelines followed
• All formatters and local linters executed and passed
• Written new unit and / or integration tests where applicable
• Protected functional changes with optionality (feature flags)
• Used internationalization (i18n) for all UI strings
• CI builds passed
• Communicated to DevOps any deployment requirements
• Updated any necessary documentation (Confluence, contributing docs) or informed the documentation team

🦮 Reviewer guidelines

• 👍 (:+1:) or similar for great changes
• 📝 (:memo:) or ℹ️ (:information_source:) for notes or general info
• ❓ (:question:) for questions
• 🤔 (:thinking:) or 💭 (:thought_balloon:) for more open inquiry that's not quite a confirmed issue and could potentially benefit from discussion
• 🎨 (:art:) for suggestions / improvements
• ❌ (:x:) or ⚠️ (:warning:) for more significant problems or concerns needing attention
• 🌱 (:seedling:) or ♻️ (:recycle:) for future improvements or indications of technical debt
• ⛏ (:pick:) for minor or nitpick changes

[github-actions]

Checkmarx One – Scan Summary & Details – fdc3f659-bf7a-4d4f-be9f-2399bf6743d5

Great job! No new security vulnerabilities introduced in this pull request

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 56.06%. Comparing base (93a28ee) to head (d50f986).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #6922      +/-   ##
==========================================
- Coverage   56.08%   56.06%   -0.02%     
==========================================
  Files        1971     1971              
  Lines       87090    87083       -7     
  Branches     7759     7759              
==========================================
- Hits        48841    48825      -16     
- Misses      36441    36450       +9     
  Partials     1808     1808              

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