[CL-319] custom back action in popup header component

[willmartian]

🎟️ Tracking

https://bitwarden.atlassian.net/browse/CL-319

📔 Objective

Add the ability to customize the back action in the popup header component.

📸 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[bot]]

Codecov Report

Attention: Patch coverage is 0% with 6 lines in your changes missing coverage. Please review.

Project coverage is 29.33%. Comparing base (9ec0142) to head (eb4f1ae). Report is 2 commits behind head on main.

Files	Patch %	Lines
...rc/platform/popup/layout/popup-header.component.ts	0.00%	3 Missing :warning:
libs/components/src/utils/index.ts	0.00%	2 Missing :warning:
libs/components/src/index.ts	0.00%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #9829 +/- ## ========================================== + Coverage 29.30% 29.33% +0.03% ========================================== Files 2532 2528 -4 Lines 73845 73759 -86 Branches 13790 13767 -23 ========================================== - Hits 21639 21637 -2 + Misses 50584 50500 -84 Partials 1622 1622 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.

[github-actions[bot]]

Checkmarx One – Scan Summary & Details – a5e98bc2-2e4d-4d2f-8305-66fc9fac824b

New Issues

Severity	Issue	Source File / Package	Checkmarx Insight
	Client_Use_Of_Iframe_Without_Sandbox	/apps/web/src/connectors/duo.ts: 8	Attack Vector

Fixed Issues

Severity	Issue	Source File / Package
	Client_DOM_Open_Redirect	/apps/browser/src/platform/popup/layout/popup-header.component.ts: 29