adds ical input to calendar html templates and implements data handling

- the icalHandler in the backend is used in two instances. First, when
  the user adds a new ical calendar into the database, routes.py passes
  the information (name and url) to the ical Handler. The calendars are
  saved in the database as type 'ical'.

  Then, when a connected device pulls current events, all the calendars
  which are of type 'ical' are pulled and parsed for current events.
  See the backend commit for details on what happens there.

- All google Calendar related functions now have an additional check,
  to make sure that the calendar they are working on is of type 'Google'.

server/template/calendar.html

@@ -36,6 +36,8 @@
     <form action="" method="post">
     <div class="container grey" style="margin-top: 3rem;">
         <div>{{ form.hidden_tag() }}</div>
+        <div style="margin: 1rem">{{ form.calName.label }}</div>
+        <div style="margin: 1rem">{{ form.calName(size=24) }}</div>
         <div style="margin: 1rem">{{ form.iCalURL.label }}</div>
         <div style="margin: 1rem">{{ form.iCalURL(size=24) }}</div>
         <div style="with: 8rem; margin: 1rem">{{ form.submit() }}</div>