Textarea placeholder does not have the option to use translated literal form like _("xxx") for i18n detection in LVGL

[Xinyu-Sheng]

Currently, the Textarea’s placeholder does not support the translated literal format like _("xxx"), preventing LVGL’s i18n tools from automatically detecting and extracting translatable strings — making multilingual development inconvenient.

We request that the Textarea placeholder provide an option to use translated literals (e.g. _("Enter text here")), so i18n tools can properly recognize and translate them.

Currently, the only workarounds are manually maintaining translation mappings or forgoing placeholder translation altogether — both of which result in poor developer experience and risk missing translations.