Add event checkin functionality, seperate power tests into a different form (#536)

* Split power related parts of event checklist into a seperate form

* Revamp H&S overview, remove individual lists.

They were not a good thing.

* Remove old 'vehicle/crew' stuff

* Very initial version of checkin form

* Further work on checkin, add role field etc

* Fix tests after form split

* Add ability to edit checkins, more validation

* Basic checkin/out logic complete

* Add homepage checkin for events happening now

* Minor improvement to homepage UI

* Checkin button turns into checkout button where applicable

* UI work

* Clicking check out does not redirect the user

* Register check in model with the admin site

* Add power record status chip, checklist status chip displays number of checklists

* Minor fixes

* Implement codedoctor suggestions

* pep8

* Add data migration for crew/vehicles

* Checkin only requires login (no perms) and block users from editing other checkins at Django level

RIGS/templates/partials/event_detail_buttons.html

@@ -49,5 +49,13 @@
         {% endif %}
 
         <a href="https://docs.google.com/forms/d/e/1FAIpQLSf-TBOuJZCTYc2L8DWdAaC3_Werq0ulsUs8-6G85I6pA9WVsg/viewform" class="btn btn-danger"><span class="fas fa-file-invoice-dollar"></span> <span class="d-none d-sm-inline">Subhire Insurance Form</span></a>
+
+        {% if event.can_check_in %}
+            {% if request.user.current_event %}
+            <a href="{% url 'event_checkout' %}" class="btn btn-warning">Check Out</a>
+            {% else %}
+            <a href="{% url 'event_checkin' event.pk %}" class="btn btn-success modal-href"><span class="fas fa-user-clock"></span> <span class="d-none d-sm-inline">Check In</span></a>
+            {% endif %}
+        {% endif %}
     {% endif %}
 </div>