This commit introduces comprehensive localization support for the application, enabling dynamic language switching and localized UI elements. Key changes include:
- Added `.resx` files for German (de-DE), English (en-US), and French (fr-FR).
- Updated Razor components to use `IStringLocalizer` for dynamic string localization.
- Introduced the `L(string key, string fallback)` helper method for consistent localized string retrieval with fallback support.
- Implemented dynamic culture initialization in `Program.cs` via an API call to `/api/Localization/lang`.
- Localized error pages, grid columns, tabs, popups, validation messages, and tooltips.
- Dynamically generated privacy policy links based on the current culture.
- Improved user experience with fully localized loading states, error handling, and UI labels.
These changes enhance accessibility and usability, making the application more user-friendly for a global audience.
Introduced a `LanguageControls` component for switching between
languages (`de-DE`, `en-US`, `fr-FR`) and integrated a new
`LocalizationService` to manage language preferences. Updated
`LocalizationController` to handle language persistence via
cookies and support multiple cultures. Enhanced the footer
layout to include the language selector alongside theme
controls.
Added `flag-icons` library for displaying country flags and
configured request localization in `Program.cs`. Styled the
language selector dropdown and improved sender page visuals
with updated CSS. Defaulted language handling to `de-DE` for
fallback scenarios. Cleaned up redundant code in
`LocalizationController`.
