[SPARK-45100][SQL][3.3] Fix an internal error from reflect()on NULL class and method

### What changes were proposed in this pull request?
In the PR, I propose to check that the `class` and `method` arguments are not a NULL in `CallMethodViaReflection`. And if they are, throw an `AnalysisException` with new error class `DATATYPE_MISMATCH.UNEXPECTED_NULL`.

This is a backport of #42849.

### Why are the changes needed?
To fix the issue demonstrated by the example:
```sql
$ spark-sql (default)> select reflect('java.util.UUID', CAST(NULL AS STRING));
[INTERNAL_ERROR] The Spark SQL phase analysis failed with an internal error. You hit a bug in Spark or the Spark plugins you use. Please, report this bug to the corresponding communities or vendors, and provide the full stack trace.
```

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

### How was this patch tested?
By running new test:
```
$ build/sbt "test:testOnly *.MiscFunctionsSuite"
```

### Was this patch authored or co-authored using generative AI tooling?
No.

Authored-by: Max Gekk <max.gekkgmail.com>
(cherry picked from commit fd424ca)

Closes #42856 from MaxGekk/fix-internal-error-in-reflect-3.3.

Authored-by: Max Gekk <[email protected]>
Signed-off-by: Max Gekk <[email protected]>

Author: MaxGekk

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

@@ -65,6 +65,8 @@ case class CallMethodViaReflection(children: Seq[Expression])
     } else if (!children.take(2).forall(e => e.dataType == StringType && e.foldable)) {
       // The first two arguments must be string type.
       TypeCheckFailure("first two arguments should be string literals")
+    } else if (children.take(2).exists(_.eval() == null)) {
+      TypeCheckFailure("first two arguments must be non-NULL")
     } else if (!classExists) {
       TypeCheckFailure(s"class $className not found")
     } else if (children.slice(2, children.length)

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

@@ -34,6 +34,14 @@ class MiscFunctionsSuite extends QueryTest with SharedSparkSession {
         s"reflect('$className', 'method1', a, b)",
         s"java_method('$className', 'method1', a, b)"),
       Row("m1one", "m1one"))
+    val e1 = intercept[AnalysisException] {
+      df.selectExpr("reflect(cast(null as string), 'fromString', a)")
+    }
+    assert(e1.getMessage.contains("first two arguments must be non-NULL"))
+    val e2 = intercept[AnalysisException] {
+      df.selectExpr("reflect('java.util.UUID', cast(null as string), a)")
+    }
+    assert(e2.getMessage.contains("first two arguments must be non-NULL"))
   }
 
   test("version") {