COPY from csv support delimeter `\r\n`

[Xuanwo]

CsvSource will accept the input delimiter directly. This behavior could make user copied wrong data when input delimiter is \n but files is \r\n.

To make users' lives easier, we can handle them by:

let record_delimiter = if record_delimiter == b'\n' || record_delimiter == b'\r' {
    Terminator::CRLF
} else {
    Terminator::Any(record_delimiter)
};

So that users will not panic when they copied the wrong data with \n.

[Xuanwo]

Cc @youngsofun, this issue seems out of date. Do we have already implement this yet?

[Xuanwo]

Fixed by #7613