snapshot: Use inline SVG icons

Tests:

- All the icons appear as before in both light/dark themes.

Signed-off-by: Sunil Mohan Adapa <sunil@medhas.org>
Reviewed-by: James Valleroy <jvalleroy@mailbox.org>

plinth/modules/snapshot/templates/snapshot_manage.html

@@ -6,6 +6,7 @@
 {% load bootstrap %}
 {% load i18n %}
 {% load static %}
+{% load plinth_extras %}
 
 {% block page_js %}
   <script src="{% static 'snapshot/snapshot.js' %}" defer></script>
@@ -58,8 +59,7 @@
                      title="{% blocktrans trimmed with number=snapshot.number %}
                            Rollback to snapshot #{{ number }}
                      {% endblocktrans %}">
-                    <span class="fa fa-repeat"
-                          aria-hidden="true"></span>
+                    {% icon 'repeat' %}
                   </a>
                 </td>
                 <td class="centered-column">

plinth/modules/snapshot/templates/snapshot_not_supported.html

@@ -5,11 +5,12 @@
 
 {% load bootstrap %}
 {% load i18n %}
+{% load plinth_extras %}
 
 {% block configuration %}
   <div id="snapshot-not-supported" class="alert alert-danger d-flex align-items-center">
     <div class="me-2">
-      <span class="fa fa-exclamation-triangle" aria-hidden="true"></span>
+      {% icon 'exclamation-triangle' %}
       <span class="visually-hidden">{% trans "Caution:" %}</span>
     </div>
     <div>