fix: generalizes player search query format

Prior to this commit, the search query was used monolithically as a
single string to match the members' member id or their (comma-separated)
full name;  this had many shortcomings, e.g., a search query " 12345 "
would fail to match a member with id "12345", and a search query
"surname name" would fail to match a member with full name "surname,
name".  Also see usgo#164 and usgo#248.

In this commit, the search is first stripped of outer whitespace, which
helps search for member ids.  If the search query is not an id, then the
search query is split into tokens, and a match with a member is found if
all of the respective query tokens match the member's full name.  This
allows users to run queries such as "name", "surname", "name surname" or
"surname name".

agagd/agagd_core/views/search.py

@@ -1,3 +1,6 @@
+import functools
+import operator
+
 from agagd_core.models import Member
 from agagd_core.tables.search import SearchResultsTable
 from django.db.models import F, Q
@@ -13,7 +16,7 @@ class SearchView(DetailView):
     search_results_template_name = "search_results.html"
 
     def get(self, request):
-        query = request.GET.get("q", "")
+        query = request.GET.get("q", "").strip()
 
         if not query:
             return TemplateResponse(request, self.template_name)
@@ -22,9 +25,14 @@ def get(self, request):
             member_id = [int(query)]
             return HttpResponseRedirect(reverse("players_profile", args=member_id))
 
+        # constructing intersection queryset from query tokens
+        tokens = query.split()
+        querysets = (Q(full_name__icontains=token) for token in tokens)
+        queryset = functools.reduce(operator.and_, querysets)
+
         member_table_data = (
             Member.objects.filter(Q(member_id=F("players__pin_player")))
-            .filter(full_name__icontains=query)
+            .filter(queryset)
             .values(
                 "member_id",
                 "chapter_id",