Added initial UI integration and plugin manager

[mdwigley]

Description

This PR extends the application bootstrap process and navigation system to enable full plugin-contributed UI integration. Plugins can now dynamically contribute styles, main navigation pages, and settings pages, which are automatically registered with the host at runtime.

Key changes include:

• Bootstrapper Enhancements

  • Loads plugin-provided style resources (IPluginStyleInclusion) into Application.Current.Styles.
  • Registers navigation pages defined by IPluginPages into MainViewModel.
  • Adds settings pages from IPluginSettingsPages into the consolidated settings hub.
  • Provides basic handling for duplicate or missing resources.

• Navigation & Settings Hub

  • Added a permanent Settings entry in navigation that opens the consolidated settings hub.
  • Introduced SettingsView / SettingsViewModel and SettingsPluginsView / SettingsPluginsViewModel.
  • Integrated a Plugin Manager to list installed plugins with basic metadata.
  • Prepared framework for plugin-specific settings integration.

Related Issue

• Resolves Enable loading and integration of plugin resources #69
• Resolves Implement Bootstrapper Enhancements for Plugin Styles, Pages, and Settings Registration #70
• Resolves Develop and Integrate Plugin Management UI in Settings Hub #71
• Resolves Update for Dynamic Plugin Pages and Settings Hub Integration #72
• Resolves Implement Error Handling and Fallback Strategies for Plugin Resource Integration #73

Motivation and Context

This change establishes the foundation for runtime UI extensibility, allowing plugins to seamlessly extend navigation, settings, and styles without manual configuration. It reduces wiring overhead for plugin developers and provides a consistent integration point for end users.

How Has This Been Tested?

Only basic smoke testing was performed using MockPlugin for basic functionality. Future updates will include proper automated test coverage.

Screenshots (if appropriate):

• NA

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Asset change (adds or updates icons, templates, or other assets)
• Documentation change (adds or updates documentation)
• Plugin change (adds or updates a plugin)

Checklist:

• I have read the CONTRIBUTING document.
• My change requires a change to the core logic.
  • I have linked the project issue above.
• My change requires a change to the assets.
  • I have linked the asset issue above.
• My change requires a change to the documentation.
  • I have linked the documentation issue above.
• My change requires a change to a plugin.
  • I have linked the plugin issue above.