[PM-12023] Enforce hmac when mac key is present

[quexten]

🎟️ Tracking

https://bitwarden.atlassian.net/issues/PM-12023
(https://bitwarden.atlassian.net/issues/PM-4185)

📔 Objective

Prevent downgrading of encstring types to hmac-less by enforcing hmac when the symmetric key used has a mac key.

⏰ 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 – d4a2b2f2-a67d-450e-bb2a-8711d2956279

No New Or Fixed Issues Found

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 58.24%. Comparing base (d23ec73) to head (022b01f).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1041      +/-   ##
==========================================
+ Coverage   58.18%   58.24%   +0.05%     
==========================================
  Files         197      197              
  Lines       13486    13504      +18     
==========================================
+ Hits         7847     7865      +18     
  Misses       5639     5639              

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