write_lance with create mode using namespace.create_table

[jackye1995]

Currently we first write the table and then do register_table.

There are technically 2 other ways to do this:

1. create_table with empty table, and then write data to it. One issue is that the table shows up before the data is fully written
2. create_table which creates a running transaction to use, which allows Ray to write data and then commit the transaction at finish time.

Currently a basic namespace probably can only do 1, since the transaction part is not fully flushed out yet.

[jackye1995]

And I think we could add another create_mode parameter that is checked when write mode is create. The mode can be register_after_write, create_before_write, and we can add create_with_transaction once that is available.

[chenghao-guo]

At this time, do we have a better approach for this? I'm currently working on some namespace integration with lance-ray. I've encountered an issue where creating an empty table first and then writing to it can lead to a schema mismatch on my end.
I'm examining the following code snippet:

                create_request = CreateEmptyTableRequest(id=table_id)
                create_response = namespace.create_empty_table(create_request)
                self.uri = create_response.location
                if create_response.storage_options:
                    merged_storage_options.update(create_response.storage_options)

In 'create' mode, when we create an empty table using only an id without a schema, most catalogs typically require a minimal schema to be provided. For instance:

            fields = [
                FieldSchema(
                    name='__placeholder_id',
                    type='bigint',
                    comment='Placeholder column for empty table'
                )
            ]

However, once such a table is created, I haven't found any API calls within lance-namespace to update its schema.
Therefore, I propose we adapt the CreateEmptyTableRequest to allow for additional parameters, such as the schema. This would enable us to correctly set the schema even when creating an empty table, allowing lance-ray to append or overwrite data subsequently without schema conflicts.