Harden search filter

* hardens search filter against whitespaces
* renames 'Show all' filter to 'Show unshared' for clarification
* adds translation

intervention/filters.py

@@ -21,7 +21,7 @@ class InterventionTableFilter(django_filters.FilterSet):
     )
     sa = django_filters.BooleanFilter(
         method='_filter_show_all',
-        label=_("Show all"),
+        label=_("Show unshared"),
         label_suffix=_(""),
         widget=forms.CheckboxInput()
     )
@@ -72,6 +72,7 @@ class InterventionTableFilter(django_filters.FilterSet):
         Returns:
 
         """
+        value = value.strip()
         # build filter expression
         q = Q(title__icontains=value) | Q(identifier__icontains=value)
         return queryset.filter(q)