feat(conversation) - add Note to self conversation

[DorraJaouad]

☑️ Resolves

• Feature Frontend "Note to self" #10405

🖼️ Screenshots

Forward a message to Note to self
https://github.com/nextcloud/spreed/assets/84044328/6335d4b9-7221-4842-8f86-0770ae325646

Restore
https://github.com/nextcloud/spreed/assets/84044328/1e3f593f-5be0-4604-9a6a-df601f829c1f

🚧 Tasks

• Remove the non-applicable settings
• Add the option to restore the note to self conversation if it was removed
• Add the option to forward a message to note to self
• Add forward message action to the store and some follow-up refactoring where it is used
• Write the relevant tests for the new action

🏁 Checklist

• ⛑️ Tests (unit and/or integration) are included or not required
• 📘 API documentation in docs/ has been updated or is not required
• 📗 User documentation in https://github.com/nextcloud/documentation/tree/master/user_manual/talk has been updated or is not required
• 🔖 Capability is added or not needed

[DorraJaouad]

What about labelling it as New personal note without capital letters, and put on a third place in the list?

I ordered it based on the usage :

• Create a new conversation - the most common action
• New personal note - taking personal notes is a useful but less common action than starting conversations and more relevant to the user on a daily basis ( it will appear only when the note to self does not exist)
• Join open conversation - viewing existing conversations is helpful but not where most users will start or use it daily.

cc @nextcloud/designers

[Antreesy]

Seems good as-is, doesn't break the previous behaviour
I've raised a follow-up and RFC issues