Add methods that allow to insert/fetch a stream of bytes in arbitrary format

[slvrtrn]

See the discussion here: #152 (comment)

For raw insert, the main use case is to insert the data from files. Similarly, with raw query, the data can be saved into a file.

• Query::fetch_bytes feat: Query::fetch_bytes #182
• Insert::write_bytes or a separate impl, such as InsertBytes

[serprex]

#182

[VladTheJunior]

Hi, is there any progress on inserting bytes feature ? I want to insert parquet data to table and can't find way to do it.

[slvrtrn]

@VladTheJunior, I am currently busy with #221; the insert bytes feature can be put back on track after that.