Extend `lupdate` to include UI type (e.g., QLabel, QPushButton) for improved translation context

Application developers often rely on automated translation tools to produce documentation in multiple languages. The quality of these translations can be significantly improved by providing translation tools with contextual information derived from the existing translations managed via Qt Linguist and stored in .ts files. This approach would help ensure that the terminology used in the translated documentation remains consistent with the language used within the application itself.

I encourage the Qt team to investigate this topic and consider enhancing the documentation on how .ts files and existing translations can be leveraged as contextual input for translating application manuals. Additionally, the team might explore creating a tool or mechanism to export both translations and their contextual information in a format suitable for AI-based translation systems.

While .ts files could potentially serve this purpose, their current structure is limited by the lack of metadata describing the type of UI element each string is associated with (e.g., QPushButton, QMenu, QAction, QLabel, etc.).

A possible minimal improvement would be to extend lupdate to optionally extract and include contextual information from .ui files—for example, by annotating entries with the corresponding UI element type when available.

As a further enhancement, it would be useful to allow developers to explicitly define semantic tags or identifiers within the translation comment fields, providing richer context for both human translators and AI-powered translation tools.