importFileReference and importUrlReference should support multi turn extraction

[feich-ms]

Is your feature request related to a problem? Please describe.
Users should be able to use composer to import kb pairs with multi turn formats from url or file which is not supported in current importFileReference and importUrlReference in qna builder

Describe the solution you'd like
add the interfaces for these two functions

Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered.

Additional context
Add any other context or screenshots about the feature request here.

[enhancement]