support uid for useInstanceOption

[kazupon]

Currently, only ce and type are supported, but adding uid support would be useful in Vue DevTools.

Background:

vue-i18n supports a Vue DevTools plugin. Internally, vue-i18n uses a concept called locale scope, similar to a component tree. Calling the useI18n composable provides i18n debugging functionality as a Vue DevTools plugin by associating the locale scope with the component instance.

I’ve heard that, In Vue 4 or future versions, obtaining the component instance using getCurrentInstance will no longer be possible. Therefore, while vue-i18n is considering changes to its internal implementation (planned to switch to a provide-inject-based approach), it still requires information about which component the locale scope is associated with.

GenericComponentInstance currently supports uid. Vue DevTools can obtain this component instance. If useInstanceOption can retrieve the uid, this information can be used to link it to the locale scope. By obtaining the uid from the component instance on the Vue DevTools side, vue-i18n can continue to support the plugin for Vue DevTools as before.

[edison1105]

useInstanceOption is used as a replacement for getCurrentInstance. It only exposes a subset of the properties from the instance. Currently, only ce and type are supported. If you need additional properties to be added, please feel free to submit a PR.