[VL][CH] Discrepancy in file path between CH and VL

### Backend

VL (Velox)

### Bug description

CH encodes file paths into ASCII in `BackendsApiManager.getTransformerApiInstance.encodeFilePathIfNeed` and `CHIteratorApi.genSplitInfo` whereas VL doesn't do that. Why is there such difference between the two engines? Is this because CH is not able to work with non-ASCII file paths?

### Gluten version

_No response_

### Spark version

None

### Spark configurations

_No response_

### System information

_No response_

### Relevant logs

```bash

```

Compare BackendsApiManager.getTransformerApiInstance.encodeFilePathIfNeed with CHIteratorApi.genSplitInfo, focusing on how each engine handles non-ASCII paths. Establish whether ClickHouse requires ASCII encoding, then document the reason or define the needed behavior and verify it with a representative non-ASCII file path.

Written by the indexing model from the issue text.