chore(pinia): migrate actor store to pinia

[DorraJaouad]

☑️ Resolves

🏁 Checklist

• 🌏 Tested with different browsers / clients:
  • Chromium (Chrome / Edge / Opera / Brave)
  • Firefox
  • Safari
  • Talk Desktop
  • Not risky to browser differences / client
• 🖌️ Design was reviewed, approved or inspired by the design team
• ⛑️ Tests are included or not possible
• 📗 User documentation in https://github.com/nextcloud/documentation/tree/master/user_manual/talk has been updated or is not required

[Antreesy]

Note: need to unify that, we have a lot of different checks in different places for that

[Antreesy]

Also follow-up: we are checking it now based on actorType:

	const isActorUser = computed(() => actorType.value === ATTENDEE.ACTOR_TYPE.USERS)
	const isActorGuest = computed(() => actorType.value === ATTENDEE.ACTOR_TYPE.GUESTS)

Because we set one of these in setCurrentUser() or setCurrentParticipant(). But actorType can be also 'emails' | 'bridged' | 'federated_users' | 'phones'

Correct way (what we actually want to check) in most places is if user logged in: userId !== null, right?

[Antreesy]

Works so far =)

[Antreesy]

Also follow-up: we are checking it now based on actorType:

	const isActorUser = computed(() => actorType.value === ATTENDEE.ACTOR_TYPE.USERS)
	const isActorGuest = computed(() => actorType.value === ATTENDEE.ACTOR_TYPE.GUESTS)

Because we set one of these in setCurrentUser() or setCurrentParticipant(). But actorType can be also 'emails' | 'bridged' | 'federated_users' | 'phones'

Correct way (what we actually want to check) in most places is if user logged in: userId !== null, right?

[Antreesy]

Tested, minor comments