Improve `SELECT text` performance

It's slower than the PostgreSQL protocol.

The followings may be related but we need to look into it:

* Building `arrow::RecordBatch` is slow?
* We need to build `arrow::RecordBatch`es to use `arrow::ipc::RecordBatchWriter()`. We need to copy PostgreSQL data for it. (Not zero-copy.)
* Should we add an API that writes Apache Arrow streaming format data without building `arrow::RecordBatch` to Apache Arrow C++?
* Calling `SPI_getbinval()` is slow?
* It calls `nocachegetattr()` https://github.com/postgres/postgres/blob/3edc6580c0e27fb8f13322efd255a88d20dda6c2/src/backend/access/common/heaptuple.c#L496-L712 and it's not a short function. Can we shortcut some operations?

首先对 SELECT 文本路径进行 profiling，并将其与 PostgreSQL 协议进行比较，重点关注 Apache Arrow RecordBatch、RecordBatchWriter 以及 PostgreSQL 的 SPI_getbinval() 的构造。确定复制到 RecordBatch 还是 SPI_getbinval()/nocachegetattr() 占主导，然后将已完成的更改与 PostgreSQL 协议基线进行测量比较。

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