[SPARK-50204][SQL] Factor out HiveTableRelation read path resolution

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

Factor out `HiveTableRelation` resolution into a separate `RelationConversions` method to reuse it in the single-pass Analyzer.

### Why are the changes needed?

Context: https://issues.apache.org/jira/browse/SPARK-49834

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

No.

### How was this patch tested?

Existing tests.

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

copilot.vim.

Closes apache#48738 from vladimirg-db/vladimirg-db/refactor-relation-converters.

Authored-by: Vladimir Golubev <vladimir.golubev@databricks.com>
Signed-off-by: Max Gekk <max.gekk@gmail.com>

sql/hive/src/main/scala/org/apache/spark/sql/hive/HiveStrategies.scala

@@ -31,7 +31,7 @@ import org.apache.spark.sql.catalyst.rules.Rule
 import org.apache.spark.sql.errors.QueryCompilationErrors
 import org.apache.spark.sql.execution._
 import org.apache.spark.sql.execution.command.{CreateTableCommand, DDLUtils, InsertIntoDataSourceDirCommand}
-import org.apache.spark.sql.execution.datasources.{CreateTable, DataSourceStrategy, HadoopFsRelation, InsertIntoHadoopFsRelationCommand, LogicalRelationWithTable}
+import org.apache.spark.sql.execution.datasources.{CreateTable, DataSourceStrategy, HadoopFsRelation, InsertIntoHadoopFsRelationCommand, LogicalRelation, LogicalRelationWithTable}
 import org.apache.spark.sql.hive.execution._
 import org.apache.spark.sql.hive.execution.HiveScriptTransformationExec
 import org.apache.spark.sql.hive.execution.InsertIntoHiveTable.BY_CTAS
@@ -240,9 +240,8 @@ case class RelationConversions(
           query, overwrite, ifPartitionNotExists, byName)
 
       // Read path
-      case relation: HiveTableRelation
-          if DDLUtils.isHiveTable(relation.tableMeta) && isConvertible(relation) =>
-        metastoreCatalog.convert(relation, isWrite = false)
+      case relation: HiveTableRelation if doConvertHiveTableRelationForRead(relation) =>
+        convertHiveTableRelationForRead(relation)
 
       // CTAS path
       // This `InsertIntoHiveTable` is derived from `CreateHiveTableAsSelectCommand`,
@@ -287,6 +286,15 @@ case class RelationConversions(
           convertProvider(storage), query, overwrite)
     }
   }
+
+  private[hive] def doConvertHiveTableRelationForRead(relation: HiveTableRelation): Boolean = {
+    DDLUtils.isHiveTable(relation.tableMeta) && isConvertible(relation)
+  }
+
+  private[hive] def convertHiveTableRelationForRead(
+      relation: HiveTableRelation): LogicalRelation = {
+    metastoreCatalog.convert(relation, isWrite = false)
+  }
 }
 
 private[hive] trait HiveStrategies {