Allow doc_id to be specified when using insert_multiple

[waylonflinn]

Currently doc_id cannot be used with insert_multiple because no check is performed for the Document class. This PR adds the same code as used in insert to insert_multiple, thus allowing doc_id to specified for any item being added.

[msiemens]

Thanks for the pull request @waylonflinn! This looks good to me. Could you add a quick test case for this in tests/test_tables.py? Then I'd be ready to merge this

[ianhinder]

It looks like this would allow you to insert documents with document IDs that already exist in the table. insert currently checks that a supplied document ID does not already exist, as far as I can see. Probably this PR should be changed to check that the provided document ID is not already in the table with a similar assertion to that used in insert.

[benetherington]

@waylonflinn If you want to pass on these requested changes, I can work on this.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Feel free to reopen this if needed. Thank you for your contributions ❤️

[ianhinder]

This issue hasn't gone away, and the PR is still useful. @waylonflinn - do you agree with my comment that an additional check should be added?

[msiemens]

This has now been implemented by #455 which has been merged 🙂