Consider migrating from vuex to pinia

[usu]

https://github.com/vuejs/vuex:

The official state management library for Vue has changed to Pinia. Pinia has almost the exact same or enhanced API as Vuex 5, described in vuejs/rfcs#271. You could simply consider Pinia as Vuex 5 with a different name. Pinia also works with Vue 2.x as well.

There is no active development anymore on vuex. As the usage of Pinia is very similar for Vue2 and Vue3, this would already help a bit towards migration to Vue3.

Also needs adjustments of hal-json-vuex (=potentially forking/renaming the package to hal-json-pinia). Would be a quick win compared to a complete rewrite of hal-json-vuex.

[BacLuc]

Maybe we achieve this without a direct dependency to pinia...or we can keep that in mind and remove the dependency later.
Is the interface similar enough, e.g. for the calendar?

[manuelmeister]

eCamp Core Decision

For the hackathon we would discuss it again, if someone would prepare the topic. Otherwise it is open for grabs if a group wants to try.