[PM-20361] Expose signing key generation to mobile and wasm clients & add to key context

[quexten]

🎟️ Tracking

https://bitwarden.atlassian.net/browse/PM-20361

📔 Objective

Adds signing keys to the key context, and adds functions to make signature keys to the sdk.

⏰ 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 – 66149e76-7999-4800-8cba-ee5cbc260683

Great job, no security vulnerabilities found in this Pull Request

[codecov]

Codecov Report

Attention: Patch coverage is 64.08840% with 65 lines in your changes missing coverage. Please review.

Please upload report for BASE (km/cose-signatures@f8044bd). Learn more about missing BASE report.

Files with missing lines	Patch %	Lines
crates/bitwarden-crypto/src/store/context.rs	50.00%	17 Missing ⚠️
crates/bitwarden-core/src/auth/login/password.rs	0.00%	11 Missing ⚠️
crates/bitwarden-core/src/mobile/crypto.rs	80.95%	8 Missing ⚠️
crates/bitwarden-core/src/auth/login/api_key.rs	0.00%	6 Missing ⚠️
crates/bitwarden-core/src/mobile/crypto_client.rs	0.00%	6 Missing ⚠️
crates/bitwarden-wasm-internal/src/crypto.rs	0.00%	6 Missing ⚠️
crates/bitwarden-core/src/auth/tde.rs	0.00%	5 Missing ⚠️
...s/bitwarden-core/src/client/encryption_settings.rs	70.00%	3 Missing ⚠️
...ates/bitwarden-core/src/auth/login/auth_request.rs	0.00%	1 Missing ⚠️
crates/bitwarden-core/src/client/test_accounts.rs	66.66%	1 Missing ⚠️
... and 1 more

Additional details and impacted files

@@                  Coverage Diff                  @@
##             km/cose-signatures     #257   +/-   ##
=====================================================
  Coverage                      ?   67.40%           
=====================================================
  Files                         ?      214           
  Lines                         ?    16639           
  Branches                      ?        0           
=====================================================
  Hits                          ?    11215           
  Misses                        ?     5424           
  Partials                      ?        0           

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

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud