PostgreSQL dictionary source

Example of settings:

SOURCE(POSTGRESQL(
    port 5432
    host 'postgresql-hostname'
    user 'postgres_user'
    password 'postgres_password'
    db 'db_name'
    table 'table_name'
    replica(host 'example01-1' port 5432 priority 1)
    replica(host 'example01-2' port 5432 priority 2)
    where 'id=10'
    invalidate_query 'SQL_QUERY'
    query 'SELECT id, value_1, value_2 FROM db_name.table_name'
))

<source>
  <postgresql>
      <host>postgresql-hostname</hoat>
      <port>5432</port>
      <user>clickhouse</user>
      <password>qwerty</password>
      <db>db_name</db>
      <table>table_name</table>
      <where>id=10</where>
      <invalidate_query>SQL_QUERY</invalidate_query>
      <query>SELECT id, value_1, value_2 FROM db_name.table_name</query>
  </postgresql>
</source>

Setting fields:

Setting	Description
`host`	The host on the PostgreSQL server. You can specify it for all replicas, or for each one individually (inside `<replica>`).
`port`	The port on the PostgreSQL server. You can specify it for all replicas, or for each one individually (inside `<replica>`).
`user`	Name of the PostgreSQL user. You can specify it for all replicas, or for each one individually (inside `<replica>`).
`password`	Password of the PostgreSQL user. You can specify it for all replicas, or for each one individually (inside `<replica>`).
`replica`	Section of replica configurations. There can be multiple sections.
`replica/host`	The PostgreSQL host.
`replica/port`	The PostgreSQL port.
`replica/priority`	The replica priority. When attempting to connect, ClickHouse traverses the replicas in order of priority. The lower the number, the higher the priority.
`db`	Name of the database.
`table`	Name of the table.
`where`	The selection criteria. The syntax for conditions is the same as for `WHERE` clause in PostgreSQL. For example, `id > 10 AND id < 20`. Optional.
`invalidate_query`	Query for checking the dictionary status. Optional. Read more in the section Refreshing dictionary data using LIFETIME.
`background_reconnect`	Reconnect to replica in background if connection fails. Optional.
`query`	The custom query. Optional.
`sslmode`	TLS/SSL mode passed to `libpq`: `disable`, `allow`, `prefer`, `require`, `verify-ca` or `verify-full`. When unset, the `libpq` default of `prefer` applies. Optional.
`sslrootcert_pem`	Contents of the CA certificate that the PostgreSQL server certificate is verified against. Optional.
`sslcert_pem`	Contents of the client certificate, for certificate-based authentication. Optional.
`sslkey_pem`	Contents of the private key belonging to `sslcert_pem`. Optional.
`sslrootcert`, `sslcert`, `sslkey`	The same credentials as paths to files on the server. Only allowed for a dictionary defined in a server configuration file, or through a named collection defined there, see below. Optional.