[SPARK-43267][JDBC] Handle postgres unknown user-defined column as string in array

### What changes were proposed in this pull request?

Spark SQL now doesn’t support creating data frame from a Postgres table that contains user-defined array column.

This PR support it as string.

### Why are the changes needed?

Support handle user-defined array column in SPARK SQL with Postgres

### Does this PR introduce _any_ user-facing change?
No

### How was this patch tested?
1. Add new test.
2. Tested in local.
```sql
CREATE DOMAIN not_null_text
    AS TEXT
    DEFAULT '';

create table films
(
    code         char(5 char)     not null
        constraint firstkey
            primary key,
    title        varchar(40 char) not null,
    did          bigint           not null,
    date_prod    date,
    kind         varchar(10 char),
    tz           timestamp with time zone,
    int_arr      integer[],
    column_name  not_null_text[],
    column_name2 not_null_text
);

INSERT INTO public.films (code, title, did, date_prod, kind, tz, int_arr, column_name, column_name2) VALUES (e'2
   ', 'fdas', 1, '2023-04-07 16:05:48', '2', null, null, null, null);
INSERT INTO public.films (code, title, did, date_prod, kind, tz, int_arr, column_name, column_name2) VALUES (e'4
   ', 'fdsa', 1, '2023-04-07 16:05:48', '4', null, null, null, null);
INSERT INTO public.films (code, title, did, date_prod, kind, tz, int_arr, column_name, column_name2) VALUES ('1    ', 'dafsdf', 1, '2023-04-04 14:43:51', '1', '2023-04-25 18:53:17.467000 +00:00', '{1,2,3}', '{1,fds,fdsa}', 'fdasfasdf');
```

Test Case
```scala
  test("jdbc array") {
    val connectionProperties = new Properties()
    connectionProperties.put("user", "system")
    connectionProperties.put("password", "system")
    spark.read.jdbc(
      url = "jdbc:postgresql://localhost:54321/test?useSSL=false&serverTimezone=UTC" +
        "&useUnicode=true&characterEncoding=utf-8",
      table = "TEST.public.films",
      connectionProperties
    ).show()
  }
```

Result
<img width="1444" alt="image" src="https://user-images.githubusercontent.com/32387433/234458027-e67e410b-c417-400d-be7e-431768afc0ef.png">

Closes #40953 from Hisoka-X/SPARK-43267_pg_array.

Lead-authored-by: Jia Fan <[email protected]>
Co-authored-by: Hisoka <[email protected]>
Signed-off-by: Kent Yao <[email protected]>

Author: Hisoka-X

connector/docker-integration-tests/src/test/scala/org/apache/spark/sql/jdbc/PostgresIntegrationSuite.scala

@@ -147,6 +147,13 @@ class PostgresIntegrationSuite extends DockerJDBCIntegrationSuite {
       |('2013-04-05 12:01:02'),
       |('2013-04-05 18:01:02.123'),
       |('2013-04-05 18:01:02.123456')""".stripMargin).executeUpdate()
+
+    conn.prepareStatement("CREATE DOMAIN not_null_text AS TEXT DEFAULT ''").executeUpdate()
+    conn.prepareStatement("create table custom_type(type_array not_null_text[]," +
+      "type not_null_text)").executeUpdate()
+    conn.prepareStatement("INSERT INTO custom_type (type_array, type) VALUES" +
+      "('{1,fds,fdsa}','fdasfasdf')").executeUpdate()
+
   }
 
   test("Type mapping for various types") {
@@ -416,4 +423,13 @@ class PostgresIntegrationSuite extends DockerJDBCIntegrationSuite {
     val df_actual = sqlContext.read.jdbc(jdbcUrl, "timestamp_ntz_roundtrip", prop)
     assert(df_actual.collect()(0) == df_expected.collect()(0))
   }
+
+  test("SPARK-43267: user-defined column in array test") {
+    val df = sqlContext.read.jdbc(jdbcUrl, "custom_type", new Properties)
+    val row = df.collect()
+    assert(row.length === 1)
+    assert(row(0).length === 2)
+    assert(row(0).getSeq[String](0) == Seq("1", "fds", "fdsa"))
+    assert(row(0).getString(1) == "fdasfasdf")
+  }
 }

sql/core/src/main/scala/org/apache/spark/sql/jdbc/PostgresDialect.scala

@@ -94,13 +94,15 @@ private object PostgresDialect extends JdbcDialect with SQLConfHelper {
     case "numeric" | "decimal" if precision > 0 => Some(DecimalType.bounded(precision, scale))
     case "numeric" | "decimal" =>
       // SPARK-26538: handle numeric without explicit precision and scale.
-      Some(DecimalType. SYSTEM_DEFAULT)
+      Some(DecimalType.SYSTEM_DEFAULT)
     case "money" =>
       // money[] type seems to be broken and difficult to handle.
       // So this method returns None for now.
       // See SPARK-34333 and https://github.com/pgjdbc/pgjdbc/issues/1405
       None
-    case _ => None
+    case _ =>
+      // SPARK-43267: handle unknown types in array as string, because there are user-defined types
+      Some(StringType)
   }
 
   override def convertJavaTimestampToTimestampNTZ(t: Timestamp): LocalDateTime = {