[Bug] Query Paimon 1.4 BLOB table fails: "Could not parse type BLOB"

[cuijunle]

Body:

### Version

- StarRocks: 3.5.x / 4.x.x / main branch
- Paimon: 1.4.1

### What's Wrong?

When accessing a Paimon 1.4 catalog table that contains BLOB type columns (a new type introduced in Paimon 1.4 for multimodal data storage), any query including `DESC table` and `SELECT` fails with the following error:

Could not parse type at position 0: expected but was .
Input type string: BLOB

### Root Cause

1. StarRocks depends on `org.apache.paimon:paimon-bundle:1.3.1`, which does not recognize the BLOB type introduced in Paimon 1.4.1
2. `ColumnTypeConverter.PaimonToHiveTypeVisitor` (FE) has no `visit(BlobType)` method, falling back to UNKNOWN_TYPE
3. `PaimonTypeUtils.PaimonToHiveTypeVisitor` (paimon-reader) has no `visit(BlobType)` method
4. `PaimonColumnValue` does not handle Blob data type for reading

### How to Reproduce?

1. Create a Paimon 1.4 table with BLOB column:
```sql
CREATE TABLE IF NOT EXISTS paimon.test.ppt_blob_test (
    file_name STRING,
    file_path STRING,
    file_size BIGINT,
    content_blob BINARY,
    ingest_time TIMESTAMP
)
TBLPROPERTIES (
    'bucket' = '-1',
    'blob-field' = 'content_blob',
    'row-tracking.enabled' = 'true',
    'data-evolution.enabled' = 'true',
    'file.format' = 'parquet',
    'parquet.compress' = 'zstd',
    'target-file-size' = '256 MB',
    'write-buffer-size' = '256 MB',
    'write-buffer-spillable' = 'true'
)

2. In StarRocks, create a Paimon catalog pointing to the warehouse:

CREATE EXTERNAL CATALOG paimon_catalog PROPERTIES (
    "type" = "paimon",
    "paimon.catalog.type" = "filesystem",
    "paimon.catalog.warehouse" = "hdfs:///path/to/warehouse"
);

3. Run any query:

DESC paimon_catalog.db.blob_table;        -- fails
SELECT * FROM paimon_catalog.db.blob_table; -- fails

Suggested Fix

1. Upgrade paimon.version from 1.3.1 to 1.4.1 in:

   • fe/pom.xml
   • java-extensions/paimon-reader/pom.xml

2. Add BlobType mapping to VARBINARY in:

   • fe/fe-core/src/main/java/com/starrocks/connector/ColumnTypeConverter.java
   • java-extensions/paimon-reader/src/main/java/com/starrocks/paimon/reader/PaimonTypeUtils.java

3. Add Blob data handling in:

   • java-extensions/paimon-reader/src/main/java/com/starrocks/paimon/reader/PaimonColumnValue.java