Mock get/set networkTimeout of java.sql.Connection in JDBC Driver to prevent HikariCP's Warning

[linghengqian]

For #32765 (comment) .

Changes proposed in this pull request:

• Mock get/set networkTimeout of java.sql.Connection in JDBC Driver to prevent HikariCP's Warning. See Fixes #638 Implement support for get/setNetworkTimeout(). pgjdbc/pgjdbc#849 .
• The default value of java.net.Socket#getSoTimeout() is normally 0. A quick test using org.apache.httpcomponents:httpclient:4.5.14,

    @Test
    public void test() throws SocketException {
        int soTimeout = org.apache.http.conn.scheme.PlainSocketFactory.getSocketFactory().createSocket().getSoTimeout();
        System.out.println(soTimeout);
    }

• Also fixes HikariCP Warning: "Driver does not support get/set network timeout for connections" brettwooldridge/HikariCP#2196 .

13:01:12.583 [main] INFO com.zaxxer.hikari.pool.PoolBase - HikariPool-1 - Driver does not support get/set network timeout for connections. (getNetworkTimeout)

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