Remove postage stamp histogram plotting

### What problem does your feature request solve?

Postage stamp histograms have a significant implementable burden, and don't make sense as a visualisation. If you were to have multiple models or members you would instead plot them as lines upon a single plot.

### Describe the solution you'd like

Postage stamp histogram plotting should be removed.

### Describe alternatives you've considered

Update the implementation of postage stamp plottings to include #1303.

Search the repository for the postage stamp histogram plotting implementation, then review issue #1303 for the related context. The work is complete when postage stamp histogram plotting has been removed and the affected plotting behavior is verified.

Written by the indexing model from the issue text.