feat: support manifest&list writer part 1

[dongxiao1198]

1 add avro writer and factory(without write func since converter pull/166 not finished yet)
2 add manifest and manifest list writer internal implement definition

[wgtmac]

I'd suggest split this PR into separate ones to make review easier. Perhaps one for avro writer, one for manifest list writer, and one for manifest file writer.

[wgtmac]

Suggested change

	class ICEBERG_EXPORT Metrics {
	public:
	Metrics() = default;
	explicit Metrics(int64_t row_count,
	std::unordered_map<int64_t, int64_t> column_sizes = {},
	std::unordered_map<int64_t, int64_t> value_counts = {},
	std::unordered_map<int64_t, int64_t> null_value_counts = {},
	std::unordered_map<int64_t, int64_t> nan_value_counts = {},
	std::unordered_map<int64_t, Literal> lower_bounds = {},
	std::unordered_map<int64_t, Literal> upper_bounds = {})
	: row_count_(row_count),
	column_sizes_(std::move(column_sizes)),
	value_counts_(std::move(value_counts)),
	null_value_counts_(std::move(null_value_counts)),
	nan_value_counts_(std::move(nan_value_counts)),
	lower_bounds_(std::move(lower_bounds)),
	upper_bounds_(std::move(upper_bounds)) {}
	private:
	int64_t row_count_ = 0;
	std::unordered_map<int64_t, int64_t> column_sizes_;
	std::unordered_map<int64_t, int64_t> value_counts_;
	std::unordered_map<int64_t, int64_t> null_value_counts_;
	std::unordered_map<int64_t, int64_t> nan_value_counts_;
	std::unordered_map<int64_t, Literal> lower_bounds_;
	std::unordered_map<int64_t, Literal> upper_bounds_;
	};
	struct ICEBERG_EXPORT Metrics {
	int64_t row_count = 0;
	std::unordered_map<int64_t, int64_t> column_sizes;
	std::unordered_map<int64_t, int64_t> value_counts;
	std::unordered_map<int64_t, int64_t> null_value_counts;
	std::unordered_map<int64_t, int64_t> nan_value_counts;
	std::unordered_map<int64_t, Literal> lower_bounds;
	std::unordered_map<int64_t, Literal> upper_bounds;
	};

What about making it a simple struct to enable aggregate initialization?

[wgtmac]

Add some comment here? e.g. Iceberg file format metrics

[wgtmac]

Suggested change

	virtual void Close() = 0;
	virtual Status Close() = 0;

[wgtmac]

Suggested change

	virtual void Close() = 0;
	virtual Status Close() = 0;

[wgtmac]

Suggested change

	virtual std::vector<int64_t> splitOffsets() = 0;
	virtual std::vector<int64_t> split_offsets() = 0;

[wgtmac]

Suggested change

	/// \brief Get the file length.
	/// \brief Get the file length.
	/// Only valid after the file is closed.

[wgtmac]

Suggested change

	/// \brief Get the file statistics.
	/// \brief Get the file statistics.
	/// Only valid after the file is closed.

[wgtmac]

Suggested change

	virtual std::shared_ptr<Metrics> metrics() = 0;
	virtual Metrics metrics() = 0;

Perhaps we can just return a simple struct instead of a shared_ptr?

[wgtmac]

Do we really need a context? Writer is much simpler than the reader impl.

[wgtmac]

Suggested change

	auto root = std::make_shared<::avro::NodeRecord>();
	ToAvroNodeVisitor visitor;
	for (const auto& field : write_schema_->fields()) {
	::avro::NodePtr node;
	ICEBERG_RETURN_UNEXPECTED(visitor.Visit(field, &node));
	root->addLeaf(node);
	}
	::avro::NodePtr root;
	ICEBERG_RETURN_UNEXPECTED(ToAvroNodeVisitor{}.Visit(*write_schema_, &root));

[dongxiao1198]

add avro writer and factory(without write func since converter pull/166 not finished yet)

ok, I will seperate them into 2 pr