[SPARK-48806][SQL] Pass actual exception when url_decode fails

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

Pass actual exception for url_decode.

Follow-up to https://issues.apache.org/jira/browse/SPARK-40156

### Why are the changes needed?

Currently url_decode function ignores actual exception, which contains information that is useful for quickly locating the problem.

Like executing this sql:
```
select url_decode('https%3A%2F%2spark.apache.org');
```
We only get the error message:
```
org.apache.spark.SparkIllegalArgumentException: [CANNOT_DECODE_URL] The provided URL cannot be decoded: https%3A%2F%2spark.apache.org. Please ensure that the URL is properly formatted and try again.
    at org.apache.spark.sql.errors.QueryExecutionErrors$.illegalUrlError(QueryExecutionErrors.scala:376)
    at org.apache.spark.sql.catalyst.expressions.UrlCodec$.decode(urlExpressions.scala:118)
    at org.apache.spark.sql.catalyst.expressions.UrlCodec.decode(urlExpressions.scala)
```
However, the actual useful exception information is ignored:
```
java.lang.IllegalArgumentException: URLDecoder: Illegal hex characters in escape (%) pattern - Error at index 1 in: "2s"
```

After this pr we will get:

```
org.apache.spark.SparkIllegalArgumentException: [CANNOT_DECODE_URL] The provided URL cannot be decoded: https%3A%2F%2spark.apache.org. Please ensure that the URL is properly formatted and try again. SQLSTATE: 22546
	at org.apache.spark.sql.errors.QueryExecutionErrors$.illegalUrlError(QueryExecutionErrors.scala:372)
	at org.apache.spark.sql.catalyst.expressions.UrlCodec$.decode(urlExpressions.scala:119)
	at org.apache.spark.sql.catalyst.expressions.UrlCodec.decode(urlExpressions.scala)
	...
Caused by: java.lang.IllegalArgumentException: URLDecoder: Illegal hex characters in escape (%) pattern - Error at index 1 in: "2s"
	at java.base/java.net.URLDecoder.decode(URLDecoder.java:237)
	at java.base/java.net.URLDecoder.decode(URLDecoder.java:147)
	at org.apache.spark.sql.catalyst.expressions.UrlCodec$.decode(urlExpressions.scala:116)
	... 135 more
```

### Does this PR introduce _any_ user-facing change?

No

### How was this patch tested?

unit test

### Was this patch authored or co-authored using generative AI tooling?

No

Closes #47211 from wForget/SPARK-48806.

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

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/urlExpressions.scala

@@ -116,7 +116,7 @@ object UrlCodec {
       UTF8String.fromString(URLDecoder.decode(src.toString, enc.toString))
     } catch {
       case e: IllegalArgumentException =>
-        throw QueryExecutionErrors.illegalUrlError(src)
+        throw QueryExecutionErrors.illegalUrlError(src, e)
     }
   }
 }

sql/catalyst/src/main/scala/org/apache/spark/sql/errors/QueryExecutionErrors.scala

@@ -374,10 +374,11 @@ private[sql] object QueryExecutionErrors extends QueryErrorsBase with ExecutionE
       cause = e)
   }
 
-  def illegalUrlError(url: UTF8String): Throwable = {
+  def illegalUrlError(url: UTF8String, e: IllegalArgumentException): Throwable = {
     new SparkIllegalArgumentException(
       errorClass = "CANNOT_DECODE_URL",
-      messageParameters = Map("url" -> url.toString)
+      messageParameters = Map("url" -> url.toString),
+      cause = e
     )
   }
 

sql/core/src/test/scala/org/apache/spark/sql/StringFunctionsSuite.scala

@@ -17,7 +17,7 @@
 
 package org.apache.spark.sql
 
-import org.apache.spark.{SPARK_DOC_ROOT, SparkRuntimeException}
+import org.apache.spark.{SPARK_DOC_ROOT, SparkIllegalArgumentException, SparkRuntimeException}
 import org.apache.spark.sql.catalyst.expressions.Cast._
 import org.apache.spark.sql.execution.FormattedMode
 import org.apache.spark.sql.functions._
@@ -1273,4 +1273,13 @@ class StringFunctionsSuite extends QueryTest with SharedSparkSession {
       )
     )
   }
+
+  test("SPARK-48806: url_decode exception") {
+    val e = intercept[SparkIllegalArgumentException] {
+      sql("select url_decode('https%3A%2F%2spark.apache.org')").collect()
+    }
+    assert(e.getCause.isInstanceOf[IllegalArgumentException] &&
+      e.getCause.getMessage
+        .startsWith("URLDecoder: Illegal hex characters in escape (%) pattern - "))
+  }
 }