DESC FUNCTION fails for TVFs with required parameters

### Version

doris master (trunk)

### What's Wrong?

`DESC FUNCTION` on TVFs with required parameters (e.g., `s3`, `hdfs`, `parquet_meta`, `partitions`, `jobs`, `tasks`, `hudi_meta`) fails with parameter validation errors. For example:

```sql
DESC FUNCTION s3();
-- ERROR: Property uri is required

DESC FUNCTION parquet_meta();
-- ERROR: Property uri or file_path is required for parquet_meta

DESC FUNCTION numbers();
-- ERROR: number not set
```

`DESC FUNCTION` only needs to display column metadata and should not trigger full TVF construction, which includes parameter validation, privilege checks, and I/O operations (S3 file listing, BE RPC, HTTP HEAD requests, etc.).

### What You Expected?

`DESC FUNCTION` should work for all TVFs regardless of whether required parameters are provided. It should only return column metadata without triggering full construction.

### How to Reproduce?

```sql
DESC FUNCTION s3();
DESC FUNCTION hdfs();
DESC FUNCTION parquet_meta();
DESC FUNCTION numbers();
```

All of the above fail with parameter validation errors.

### Are you willing to submit PR?

Yes