New importkaggledialog

Description

Added importkaggledialog for searching, downloading and importing datasets from kaggle.com
The dialog is under File > Import > From Kaggle...
Make sure kaggle command is available

Conformity

• [ ] Changelog entry
• [ ] Unit tests
• [ ] Update INSTALL
• [ ] Downport
• Fixes:

When external dependencies are removed

• [ ] Reporting to ...