Support binary data transfer in COPY FROM

[ahoppen]

Depends on #566

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My benchmark of transferring the integers from 0 to 1,000,000 both as an integer and as a string was about the same speed as the old text-based transfer. I believe that the binary transfer will start to show significant benefits when transferring binary data, other fields that don't need to be represented as fields and also means that the user doesn't need to worry about escapping their data.

A call to binary transfer data looks as follows

let records: [(id: Int, name: String)] = [(1, "Alice"), (42, "Bob")]
try await conn.copyFromBinary(table: "copy_table", columns: ["id", "name"], logger: .psqlTest) { writer in
    for record in records {
        try await writer.writeRow { columnWriter in
            try columnWriter.writeColumn(Int32(record.id))
            try columnWriter.writeColumn(record.name)
        }
    }
}