Rename generic layer.sql to actual_layer_name .sql (#1034)

Following layers had generic `layer.sql` name.

- `aerodrome_label`
- `aeroway`
- `housenumber`
- `mountain_peak`
- `park`
- `place`
- `poi`
- `transportation`
- `transportation_name`
- `water_name`

This PR renames `layer.sql` to `aerodrome_label.sql`, `aeroway.sql`...

layers/place/place.yaml

@@ -72,7 +72,7 @@ schema:
   - ./update_island_point.sql
   - ./update_state_point.sql
   - ./update_city_point.sql
-  - ./layer.sql
+  - ./place.sql
 datasources:
   - type: imposm3
     mapping_file: ./mapping.yaml