fixes adapter issues and fixes block for segments adapter

src/wagtail_personalisation/adapters.py

@@ -97,8 +97,11 @@ class SessionSegmentsAdapter(BaseSegmentsAdapter):
         :rtype: wagtail_personalisation.models.Segment or None
 
         """
-        return next(item for item in self.request.session['segments']
-                    if item.id == segment_id)
+        try:
+            return next(item for item in self.request.session['segments']
+                        if item['id'] == segment_id)
+        except StopIteration:
+            return None
 
     def add(self, segment):
         """Add a segment to the request session.

src/wagtail_personalisation/templatetags/wagtail_personalisation_tags.py

@@ -3,7 +3,6 @@ from django.template import TemplateSyntaxError
 from django.template.base import FilterExpression, kwarg_re
 from django.utils.safestring import mark_safe
 
-from wagtail_personalisation.app_settings import segments_adapter
 from wagtail_personalisation.models import Segment
 
 register = template.Library()
@@ -81,7 +80,7 @@ class SegmentNode(template.Node):
             return ""
 
         # Check if user has segment
-        user_segment = segments_adapter.get_segment(segment_id=segment.pk)
+        user_segment = context['request'].segment_adapter.get_segment(segment_id=segment.pk)
         if not user_segment:
             return ""