[dataquery] CSV upload with sessions selection

[adamdaudrich]

Describe the bug
I'm able to upload a 2 column .csv file and dqt assumes that my 2nd column is visit label

To Reproduce
Steps to reproduce the behavior (attach screenshots if applicable):

1. Go to Reports / Data Query Tool (Beta)
2. in Available Fields, select Candidate Identifiers and select CandID
3. . Click Add Filters in Next Steps at bottom right hand page
4. Click `Import from CSV'
5. tick

• Sessions
• PSCID
• No

upload the following .csv file:

pscid_ddcid_noHeader.csv

What did you expect to happen?
I expected an error here because this .csv file does not contain any Visit Label. Instead the following screen was shown

Perhaps documentation could specify that visitLabel must be in second column if csvType 'session' is selected.

Browser Environment (please complete the following information):

• OS: [Linus Ubuntu]
• Browser [firefox]
• Version [e.g. 22]

Server Environment (if known):
Note: We only support the most recent release of LORIS.

• LORIS Version: [e.g. 22.0.0]
• Linux distribution and Version: [e.g. Ubuntu 16.04, CentOS 7]
• MySQL/MariaDB Version: [e.g. MySQL 5.7, MariaDB 10.3]

Additional context
Add any other context about the problem here.