Remove calls to client_settings namespace

[Hinton]

🎟️ Tracking

📔 Objective

Now that we expose ClientSettings and DeviceType directly in the root bitwarden crate we can make the client_settings module private. I also added README files to the newly created crates that missed them.

⏰ 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[bot]]

Checkmarx One – Scan Summary & Details – 9e003674-4ab4-47c2-820f-efa465ab94cd

No New Or Fixed Issues Found

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 60.30%. Comparing base (32ac1e4) to head (ecf0ddb).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #848 +/- ## ======================================= Coverage 60.30% 60.30% ======================================= Files 189 189 Lines 12361 12361 ======================================= Hits 7454 7454 Misses 4907 4907 ```

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