bf luis:cross-train imports don't work correctly

[gabog]

Versions

@microsoft/botframework-cli/4.14.0-dev.20210416.ab0fc09 win32-x64 node-v14.15.4

Describe the bug

Running bf luis:crosstrain on a composer project that has qna dialogs with imports does not generate the proper dialogs

To Reproduce

Steps to reproduce the behavior:

1. Open composer and create a basic assistant bot (don't run or configure the bot)
   
2. Close composer, open a command prompt and navigate to source folder
3. Run the following commands (ensure the bin and obj folders are deleted)

rmdir bin
rmdir obj
mkdir generated/interruption
bf luis:cross-train --in . --out generated/interruption --config settings/cross-train.config.json --force

4. Go to the generated/interruption folder and note the following:
   

• There is a chitchat_professional.source.en-us.qna file (that shouldn't be there)
• ChitchatDialog.en-us.qna is empty (it should contain the content from chitchat_professional.source.en-us.qna

Expected behavior

luis:cross-train should have resolved the import in dialogs\ChitchatDialog\knowledge-base\en-us\ChitchatDialog.en-us.qna and included that content into the generated folder file and it didn't.

Note also that the bin folder also contains copies of the generated folder and that also cause problems in the cross-train operation (we should probably exclude the bin and obj folders from cross-train)