[Refactoring] Improve vuex store usage

Description

• Update the current application (pages/components) to use the vuex store.
• Use store modules to encapsulate behavior.

Task

Update pages and corresponding components if needed:

• Update contacts
• Update platforms
• Update devices
• Update configurations

Reference

• nuxt store
  • https://nuxtjs.org/docs/directory-structure/store/
• nuxt typescript store
  • https://typescript.nuxtjs.org/cookbook/store/

Mentions

• @tim.eder
• @tobias.kuhnert