[PM-14454] Add bit-menu-panel and bitmenuitem to environment selector dropdown

[alec-livefront]

🎟️ Tracking

https://bitwarden.atlassian.net/browse/PM-14454?atlOrigin=eyJpIjoiM2UzNDY3OTg2MjhkNDA0NTliMzVlOWYyNDM1ODM0YmQiLCJwIjoiaiJ9

📔 Objective

Adds a bit-menu-panel class to the dropdown div and a bitmenuitem attribute to the buttons of the environment selector. Adds unique data-testid to the dropdown and menu items. QA should be able to use these test IDs in their automation.

📸 Screenshots

⏰ 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

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 33.62%. Comparing base (f33661c) to head (f52026d).
Report is 6 commits behind head on main.

✅ All tests successful. No failed tests found.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #11866      +/-   ##
==========================================
- Coverage   33.63%   33.62%   -0.01%     
==========================================
  Files        2821     2821              
  Lines       88115    88115              
  Branches    16784    16784              
==========================================
- Hits        29635    29628       -7     
- Misses      56160    56167       +7     
  Partials     2320     2320              

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