Add support for Prefer: count=planned/estimated on GET /table (#1386)

test/fixtures/privileges.sql

@@ -101,6 +101,8 @@ GRANT ALL ON TABLE
     , pgrst_reserved_chars
     , authors_w_entities
     , openapi_types
+    , getallprojects_view
+    , get_projects_above_view
 TO postgrest_test_anonymous;
 
 GRANT INSERT ON TABLE insertonly TO postgrest_test_anonymous;