[PM-7826] `NotificationsService` Refactor

[justindbaur]

🎟️ Tracking

📔 Objective

Refactor NotificationsService so that it is less messaging based and more reactive to the details it cares about. This removes its updateConnection call that if called in the wrong place could cause us to open multiple connections. This is replaced with just a start call (that is more resilient to when it is ran). It also creates a special foreground instance just for browser that throws an immediate error if any of it's methods are called.

This also hopefully carves an extensibility point for dropping in a WebPush implementation a little bit easier.

📸 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 28.76712% with 104 lines in your changes missing coverage. Please review.

Project coverage is 29.39%. Comparing base (d7bf0fe) to head (50f4196). Report is 8 commits behind head on main.

Files	Patch %	Lines
...atform/notifications/signalr-connection.builder.ts	0.00%	38 Missing :warning:
...orm/notifications/default-notifications.service.ts	58.57%	29 Missing :warning:
...atform/notifications/noop-notifications.service.ts	0.00%	7 Missing :warning:
apps/browser/src/background/main.background.ts	0.00%	4 Missing :warning:
.../notifications/foreground-notifications.service.ts	0.00%	4 Missing :warning:
libs/common/src/platform/notifications/internal.ts	0.00%	4 Missing :warning:
apps/browser/src/background/runtime.background.ts	0.00%	3 Missing :warning:
apps/desktop/src/app/services/init.service.ts	0.00%	3 Missing :warning:
libs/angular/src/services/jslib-services.module.ts	0.00%	3 Missing :warning:
apps/browser/src/popup/services/services.module.ts	0.00%	2 Missing :warning:
... and 6 more

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #9843 +/- ## ========================================== + Coverage 29.32% 29.39% +0.06% ========================================== Files 2527 2534 +7 Lines 73760 73770 +10 Branches 13770 13768 -2 ========================================== + Hits 21630 21684 +54 + Misses 50508 50463 -45 - Partials 1622 1623 +1 ```

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[github-actions[bot]]

Checkmarx One – Scan Summary & Details – 2b14214d-9b3f-4d73-88cb-1892264cd551

New Issues

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