Added new localized strings to `Model.en.resx`, `Model.fr-FR.resx`,
and `Model.resx` for additional features/settings in English,
French, and German. Updated `SenderEditorPage.razor` to inject
`ModelLocalizer` and modified the `L` function to prioritize
localized strings from `ModelLocalizer` over `UiLocalizer`.
Included `@using EnvelopeGenerator.Domain.Resources` to ensure
access to the `Model` resource file. These changes improve
localization flexibility and maintainability.
Added `Model.fr-FR.resx` to support French localization.
Defined XML schema for the resource file structure, including
metadata, assembly, and data elements. Added localized
French strings for various application messages, ensuring
proper display when the locale is set to `fr-FR`.
