split up table creation SQL into separate files

lib-sql/tables/nominatim_properties.sql

@@ -0,0 +1,12 @@
+-- SPDX-License-Identifier: GPL-2.0-only
+--
+-- This file is part of Nominatim. (https://nominatim.org)
+--
+-- Copyright (C) 2026 by the Nominatim developer community.
+-- For a full list of authors see the git log.
+
+DROP TABLE IF EXISTS nominatim_properties;
+CREATE TABLE nominatim_properties (
+    property TEXT NOT NULL,
+    value TEXT
+);