feat(dotsql): support set file size to new scanner

[yangwenmai]

Support more than the bufio.MaxScanTokenSize, if not read the incomplete.

[qustavo]

any spec for this?

[yangwenmai]

When your load file is huge, you must be set size > bufio.MaxScanTokenSize.
You can review in https://golang.org/pkg/bufio/#Scanner.Buffer

[qustavo]

Could you reproduce the bug through a test so that I can better understand it?
Thanks!

[yangwenmai]

sql, err := dotsql.LoadFromFile(filePath)
if err != nil {
    log.Fatalf("load sql file error: %s", err)
}

You must be add huge content (>65536 bytes) in this filePath, we get sql, but Can't read all you set content.