[Feature Request] Update reference columns should remove non complete building block

[Freymaurer]

Is your feature request related to a problem? Please describe.
A user could delete the visible main column and the reference columns would stay. If we want to keep the "Update reference columns" logic, these need to be removed.

Describe the solution you'd like
Have "Update reference columns" remove uncomplete building blocks.

[caroott]

Alternatively, you could consider adding a "Delete Column" function which removes a column together with its reference columns. This way the problem you described ideally wont occur as long as columns are removed correctly.

[Freymaurer]

Done! Will be live with the next version (0.4.0)