Implement full internationalization (i18n) capabilities to the dashboard

[joelvandal]

Description

Implement full internationalization (i18n) capabilities to the dashboard, allowing users to create multilingual interfaces with runtime language switching.

Core Features:

• Add centralized i18n Vuex store module for locale management
• Implement runtime language switching with persistent locale storage
• Support translation objects for widget properties (label, content, text, tooltip)
• Enable dynamic translation of page and group names in navigation

Widget Support:

• Add translation support for ui-button, ui-text, ui-markdown labels/content
• Support translated tooltips in ui-text-input and ui-number-input
• Enable label translations in ui-switch, ui-slider, ui-chart, ui-gauge
• Add comprehensive translation handling for ui-form fields

Language Selector Widget:

• Create new ui-language-selector widget for runtime language switching
• Support both UI-scoped (ex. app bar) and group-scoped deployment modes
• Implement teleport functionality for application placement
• Configure output formats: code only, full object, or auto mode

Translation Features:

• Support JSON-based translation objects in widget properties
• Automatic fallback to original values
• Preserve original values for reference
• Support browser language auto-detection

Related Issue(s)

Checklist

• [x] I have read the contribution guidelines
• [x] Suitable unit/system level tests have been added and they pass
• [ ] Documentation has been updated
  • [ ] Upgrade instructions
  • [ ] Configuration details
  • [ ] Concepts
• [ ] Changes flowforge.yml?
  • [ ] Issue/PR raised on FlowFuse/helm to update ConfigMap Template
  • [ ] Issue/PR raised on FlowFuse/CloudProject to update values for Staging/Production

Labels

• [ ] Includes a DB migration? -> add the area:migration label