[SPARK-37013][SQL][FOLLOWUP] Add legacy flag for the breaking change …

…of forbidding %0$ usage in format_string

### What changes were proposed in this pull request?
Adds a legacy flag `spark.sql.legacy.allowZeroIndexInFormatString` for the breaking change introduced in #34313 and #34454 (followup).

The flag is disabled by default. But when it is enabled, restore the pre-change behavior that allows the 0 based index in `format_string`.

### Why are the changes needed?
The original commit is a breaking change, and breaking changes should be encouraged to add a flag to turn it off for smooth migration between versions.

### Does this PR introduce _any_ user-facing change?
With the default value of the conf, there is no user-facing difference.
If users turn this conf on, they can restore the pre-change behavior.

### How was this patch tested?
Through unit tests.

Closes #36101 from anchovYu/flags-format-string-java.

Authored-by: Xinyi Yu <xinyi.yu@databricks.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>
(cherry picked from commit b7af2b3)
Signed-off-by: Wenchen Fan <wenchen@databricks.com>

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

@@ -1808,7 +1808,9 @@ case class ParseUrl(children: Seq[Expression], failOnError: Boolean = SQLConf.ge
 case class FormatString(children: Expression*) extends Expression with ImplicitCastInputTypes {
 
   require(children.nonEmpty, s"$prettyName() should take at least 1 argument")
-  checkArgumentIndexNotZero(children(0))
+  if (!SQLConf.get.getConf(SQLConf.ALLOW_ZERO_INDEX_IN_FORMAT_STRING)) {
+    checkArgumentIndexNotZero(children(0))
+  }
 
 
   override def foldable: Boolean = children.forall(_.foldable)

sql/catalyst/src/main/scala/org/apache/spark/sql/internal/SQLConf.scala

@@ -2015,6 +2015,17 @@ object SQLConf {
       .booleanConf
       .createWithDefault(false)
 
+  val ALLOW_ZERO_INDEX_IN_FORMAT_STRING =
+    buildConf("spark.sql.legacy.allowZeroIndexInFormatString")
+      .internal()
+      .doc("When false, the `strfmt` in `format_string(strfmt, obj, ...)` and " +
+        "`printf(strfmt, obj, ...)` will no longer support to use \"0$\" to specify the first " +
+        "argument, the first argument should always reference by \"1$\" when use argument index " +
+        "to indicating the position of the argument in the argument list.")
+      .version("3.3")
+      .booleanConf
+      .createWithDefault(false)
+
   val USE_CURRENT_SQL_CONFIGS_FOR_VIEW =
     buildConf("spark.sql.legacy.useCurrentConfigsForView")
       .internal()

sql/core/src/test/scala/org/apache/spark/sql/errors/QueryCompilationErrorsSuite.scala

@@ -19,6 +19,7 @@ package org.apache.spark.sql.errors
 
 import org.apache.spark.sql.{AnalysisException, IntegratedUDFTestUtils, QueryTest}
 import org.apache.spark.sql.functions.{grouping, grouping_id, sum}
+import org.apache.spark.sql.internal.SQLConf
 import org.apache.spark.sql.test.SharedSparkSession
 
 case class StringLongClass(a: String, b: Long)
@@ -94,12 +95,14 @@ class QueryCompilationErrorsSuite extends QueryTest with SharedSparkSession {
   }
 
   test("ILLEGAL_SUBSTRING: the argument_index of string format is invalid") {
-    val e = intercept[AnalysisException] {
-      sql("select format_string('%0$s', 'Hello')")
+    withSQLConf(SQLConf.ALLOW_ZERO_INDEX_IN_FORMAT_STRING.key -> "false") {
+      val e = intercept[AnalysisException] {
+        sql("select format_string('%0$s', 'Hello')")
+      }
+      assert(e.errorClass === Some("ILLEGAL_SUBSTRING"))
+      assert(e.message ===
+        "The argument_index of string format cannot contain position 0$.")
     }
-    assert(e.errorClass === Some("ILLEGAL_SUBSTRING"))
-    assert(e.message ===
-      "The argument_index of string format cannot contain position 0$.")
   }
 
   test("CANNOT_USE_MIXTURE: Using aggregate function with grouped aggregate pandas UDF") {