Allow port to be configurable

Regex:

- `^`        Line start
- `#*\s*`    Find line even if commented out
- `(port)`   'port' -- capture as backreference `\1`
- `\s*=\s*`  Equals sign, whether or not surrounded by whitespace
- `\d{4,5}`  Existing port value, expected at 4/5 digits
- `(.*)`     Remainder (i.e. comment) -- capture as backreference `\2`
- `$`        Line end

postgres/macros.jinja

@@ -23,6 +23,7 @@
 {{ state }}-{{ name }}:
   {{ state }}.{{ ensure|default('present') }}:
     {{- format_kwargs(kwarg) }}
+    - db_port: {{ postgres.port|default(postgres.default_port) }}
     - onchanges:
       - test: postgres-reload-modules