Add AppendRow function to BatchColumn

[pikot]

Summary

• add function to batch column. usecase:
  I have data in rows and want to use batch column insert. Logic with creating columns arrays, and iterate this array in Append, looks like overkill. Enough iterate my data rows and call AppendRow without creating column arrays.
• smallfix for date test

Checklist

• Unit and integration tests covering the common scenarios were added

[jkaflik]

Thanks @pikot . Great work!