Add deltachat credentials page with QR code, update translation strings

app/templates/deltachat_creds.html

@@ -0,0 +1,24 @@
+{% extends "base.html" %}
+
+{% block content %}
+    <h1 class="title is-large butter-title">{{ _('Secure Messenger Account') }}</h1>
+
+
+<div class="block">
+<div class="block">
+<p>{{ _('Scan the following QR code with a device where DeltaChat is installed:') }}</p>
+</div>
+    <img src="{{ base64img }}"/>
+</div>
+<div class="block">
+    <div class="block"><p class="">{{ _('If your device does not have a camera, select "Create new profile" in DeltaChat, choose "Use Other Server" and find "Paste from clipboard", to paste the following link') }}:</p></div>
+    <pre>{{ dclink}}</pre>
+</div>
+
+    <div class="block"></div>
+<form action="{{ url_for('deltachat_credentials') }}" method="post">
+    <button type="submit" class="button is-link is-fullwidth block">
+        <p>{{ _("Generate new credentials") }} </p>
+    </button>
+ </form>
+{% endblock %}