fix(console): console pages render in standards mode and fit the window

console-base.html had no doctype, so the noVNC and serial console pages
rendered in quirks mode, where body and #main_container got their height
from the viewport. The console area overflowed the window: the full noVNC
page scrolled by the navbar height, the lite page's canvas and the serial
terminal ran below the bottom edge, hiding the last rows.

With the doctype, #main_container is a viewport-high flex column and the
console area (the noVNC container or the terminal) takes the space below
the navbar. Without that, the lite page's canvas collapsed to 0x0.

console/templates/console-base.html

@@ -1,6 +1,7 @@
 {% load static %}
 {% load i18n %}
-{% get_current_language as LANGUAGE_CODE %}<html lang="{{ LANGUAGE_CODE }}">
+{% get_current_language as LANGUAGE_CODE %}<!DOCTYPE html>
+<html lang="{{ LANGUAGE_CODE }}">
 
 <head>
     <meta charset="utf-8">
@@ -11,11 +12,17 @@
     <link href="{% static "css/webvirtcloud.css" %}" rel="stylesheet">
 
     <style>
+        body {
+            padding-bottom: 0;
+        }
+
         #main_container {
             padding: 0;
             width: 100%;
             max-width: none;
-            height: 100%;
+            height: 100vh;
+            display: flex;
+            flex-direction: column;
             background-color: #494949;
             border-bottom-right-radius: 850px 600px;
 

console/templates/console-xterm.html

@@ -9,6 +9,9 @@
 <script src="{% static 'js/xterm/addon-fit.js' %}"></script>
 
 <script src="{% static 'js/socket.io.js' %}"></script>
+<style>
+    #terminal { flex: 1; min-height: 0; }
+</style>
 
 {% endblock %}
 {% block content %}
@@ -17,7 +20,7 @@
     <button id="button" type="button" onclick="myFunction();">Connect</button>
 </div>
 
-<div style="width: 100%; height:100%;" id="terminal"></div>
+<div id="terminal"></div>
 <script>
         // socketiod is behind this page's own /socket.io/ location; the page's
         // signed token is the credential (the cookie holds the last console's)