[CH] Different behavior on function regexp_extract with spark

### Backend

CH (ClickHouse)

### Bug description

select regexp_extract('1-A', '([0-9][[\.][0-9]]*)', 1)

Spark behavior:
`1`
actual behavior:
``

### Spark version

None

### Spark configurations

_No response_

### System information

_No response_

### Relevant logs

_No response_

Reproduce the provided regexp_extract query against the ClickHouse backend and compare its result with the stated Spark result of `1`. Trace the implementation of this function and add coverage for the example; done means the query returns the Spark-compatible result without regressing related regular-expression cases.

Written by the indexing model from the issue text.