1.0.0-alpha1: possible to add cards when in archive view

[cloud2018]

Describe the bug
It's possible to add cards when showing only archieved cards

To Reproduce
Steps to reproduce the behavior:

1. Open a board
2. Click on "show archived cards"
3. Click on "+" to add card
4. Error: it's possible to add card

Expected behavior

1. Like in previous version of deck, there should be no "+" icon to add a card, when only archived cards are shown
2. Like in previous version of deck, there should be "Archived cards" right of the boards name

Screenshots
alpha version:

previous version: