fix: icontains filter for components namespace

Author: StefanFl

backend/application/core/api/filters.py

@@ -539,6 +539,7 @@ class Meta:
 
 class ComponentFilter(FilterSet):
     name_version = CharFilter(field_name="name_version", lookup_expr="icontains")
+    purl_namespace = CharFilter(field_name="purl_namespace", lookup_expr="icontains")
     # has_active_observations, has_inactive_observations and has_licenses are annotated in get_components()
     has_active_observations = BooleanFilter(field_name="has_active_observations")
     has_inactive_observations = BooleanFilter(field_name="has_inactive_observations")