Why are the changes needed?

Environment:
format: mixed_hive/hive
Engine: spark 3.3
Catalog: SparkUnifiedSessionCatalog with mixed_hive format

bug:
Spark SQL cannot recognize a successfully registered Hive UDF

description

spark-sql> reload jar hdfs:///tmp/spark_udf-1.0-SNAPSHOT.jar;
spark-sql> create function hive_db.StringUdf as 'org.example.udf.StringUdf' using jar 'hdfs:///tmp/spark_udf-1.0-SNAPSHOT.jar';
Error in query: Function 'hive_db.StringUdf' already exists in database 'hive_db'
spark-sql> select id,hive_db.StringUdf(name) from amoro_like;
Error in query: Undefined function: hive_db.StringUdf; line 1 pos 10
spark-sql> select id,hive_db.StringUdf(name) from tbl_schema_chg;
Error in query: Undefined function: hive_db.StringUdf; line 1 pos 10
spark-sql>

Brief change log

• fix load_function logic

How was this patch tested?

• Add some test cases that check the changes thoroughly including negative and positive cases if possible

• Add screenshots for manual tests if appropriate

• Run test locally before making a pull request

Documentation

• Does this pull request introduce a new feature? (yes / no)
• If yes, how is the feature documented? (not applicable / docs / JavaDocs / not documented)