Import project

[zoltanszocs]

Checklist

• [ ] Keep pull requests small so they can be easily reviewed.
• [ ] Update the documentation, please follow the numpy style guide.
• [ ] Update tests.
• [ ] Categorize the PR by setting a good title and adding one of the labels: bug, feature, ui, change, documentation, breaking, ci as they show up in the changelog.
• [ ] Link this PR to related issues by using closing keywords.
• [ ] Add a milestone to the PR for the intended release.
• [ ] Request a review from another developer.

[zoltanszocs]

• Added a bit more space between components - I was not entirely sure where you wanted more space, increasing the global spacing in the layout seemed strange. Let me know how this looks.
• Added status label at the bottom, displaying what is the next necessary step: load catalogue, select project, project already exists
• Added handling for the case when there is no valid catalogue loaded
• Added busy indication for the catalogue loading and project importing
• Added new activate checkbox and functionality