Dashboard size of columns should be changeable and stored

[dgoetz]

Is your feature request related to a problem? Please describe.

Icinga Web 2 has fixed column sizes based on screen resolution, in some cases it would be better to have different column sizes matching the use case like a operator view which should always have all three (smaller) columns independently from the screen resolution. In some cases having even more columns than the maximum 3 would be nice.

Describe the solution you'd like

I would like to adjust the column size per drag and drop and perhaps even store them to the dashboard config.

Describe alternatives you've considered

Having an additional border for the screen resolution where you get 4 columns would solve some but not all use cases.

Additional context

ref/NC/609335

[nilmerg]

That's covered by #3809. Closed as duplicate.