Hide tabs based on user authorization levels

[WilliamBZA]

Adds a Pinia UserPermissionsStore that fetches a permission summary + full descriptor from ServiceControl, then hides nav-menu items (PageHeader.vue) and Configuration sub-tabs (ConfigurationView.vue) the current user lacks rights for. Also adds a new User Permissions config page that renders the permission matrix, plus capability detection in EnvironmentAndVersionsStore.

Reviewer Checklist

• Components are broken down into sensible and maintainable sub-components.
• Styles are scoped to the component using it. If multiple components need to share CSS, then a .css file is created containing the shared CSS and imported into component scoped style sections.
• Naming is consistent with existing code, and adequately describes the component or function being introduced
• Only functions utilizing Vue state or lifecycle hooks are named as composables (i.e. starting with 'use');
• No module-level state is being introduced. If so, request the PR author to move the state to the corresponding Pinia store.

[ramonsmits]

Added some improvement on:

• #3036