[Subtask] overview the interface semantics for lakehouse table operations

[mchades]

Describe the subtask

We have added the external method to the table API: https://github.com/apache/gravitino/blob/d8a4ded1be927f24fd4ea490a6db36024731d83b/api/src/main/java/org/apache/gravitino/rel/Table.java#L122-L131

This means we will distinguish the metadata operations and data operations for external tables. This may conflict with the existing table operation interface semantics, so we need to review the existing table operation interface semantics to make them correctly support external tables and managed tables.

Parent issue

#8828