Restructure to generate backend data from `pg_catalog.pg_settings` about pgconfig-ce

[rustprooflabs]

CREATE SCHEMA pgconfig;

DROP VIEW IF EXISTS pgconfig.settings;
CREATE VIEW pgconfig.settings AS
SELECT name, setting, context, source, reset_val, boot_val,
        unit, category,
        name || ' = ' ||  setting AS postgresconf_line,
        name || ' = ' || boot_val AS default_config_line,
        short_desc,
        CASE WHEN name LIKE 'lc%'
                THEN True
            WHEN name IN ('application_name', 'TimeZone')
                THEN True
            ELSE False
            END AS frequent_override,
        CASE WHEN boot_val = reset_val THEN True 
            ELSE False 
            END AS system_default,
        CASE WHEN reset_val = setting THEN False 
            ELSE True
            END AS session_override, 
        pending_restart
    FROM pg_catalog.pg_settings
;


SELECT postgresconf_line, *
    FROM pgconfig.settings
    WHERE default_config_line IS NOT NULL
        AND NOT frequent_override
;

[rustprooflabs]

Done via #17