[Improvement] Refactor the table implementation in spark-connector

### What would you like to be improved?

Refactor the table implementation in spark-connector.

The purpose of inheritance `SparkTable` is in order to go through the `isIcebergTable` check in `IcebergSparkSqlExtensionsParser`.

For details, please refer to: https://github.com/apache/iceberg/blob/main/spark/v3.4/spark-extensions/src/main/scala/org/apache/spark/sql/catalyst/parser/extensions/IcebergSparkSqlExtensionsParser.scala#L127-L186

Without refactoring, row-level operations cannot be performed.

### How should we improve?

_No response_

Start by reading IcebergSparkSqlExtensionsParser.scala at the linked lines, then locate the SparkTable implementation in spark-connector and determine how the isIcebergTable check relates to it. The issue provides no named tests or target files; done means the refactored table implementation permits row-level operations.

Written by the indexing model from the issue text.