feat: Support serde for FileScanConfig batch_size

[westhide]

Which issue does this PR close?

• Closes None.
• Reference Support serde for batch_size

Rationale for this change

Support serde for FileScanConfig batch_size

When FileScanConfig call open(..), will set batch_size for file_source, so this PR add batch_size property for struct FileScanConfig to support serde batch_size to proto.

datafusion/datafusion/datasource/src/file_scan_config.rs

Lines 172 to 190 in 19dd46d

	impl DataSource for FileScanConfig {
	fn open(
	&self,
	partition: usize,
	context: Arc<TaskContext>,
	) -> Result<SendableRecordBatchStream> {
	let object_store = context.runtime_env().object_store(&self.object_store_url)?;
	let source = self
	.file_source
	.with_batch_size(context.session_config().batch_size())
	.with_schema(Arc::clone(&self.file_schema))
	.with_projection(self);
	let opener = source.create_file_opener(object_store, self, partition);
	let stream = FileStream::new(self, partition, opener, source.metrics())?;
	Ok(Box::pin(stream))
	}

What changes are included in this PR?

Are these changes tested?

Are there any user-facing changes?

[alamb]

Thank you @westhide

Should we remove the batch_size from JSON source too?

datafusion/datafusion/datasource-json/src/source.rs

Line 254 in dd9c3a8

batch_size: Option<usize>,

[alamb]

perhaps we can use uint64 as batch_size is a usize 🤔

[westhide]

Fixed

[westhide]

Thank you @westhide

Should we remove the batch_size from JSON source too?

datafusion/datafusion/datasource-json/src/source.rs

Line 254 in dd9c3a8

batch_size: Option<usize>,

Can we add context: Arc<TaskContext> to the create_file_opener args? The default batch_size is from context.session_config().batch_size(). If we remove batch_size property in JsonSource, we need to get the default value by context

pub trait FileSource: Send + Sync {
    /// Creates a `dyn FileOpener` based on given parameters
    fn create_file_opener(
        &self,
        object_store: Arc<dyn ObjectStore>,
        base_config: &FileScanConfig,
        partition: usize,
    ) -> Arc<dyn FileOpener>;
    // ...
}

[comphead]

lgtm thanks @westhide and @alamb for review