Implement new sample diversity visualization

[pverscha]

It would be a very nice addition for our tool to provide support for a new visualization that can be used for visualising the diversity in a sample.

A good example of this visualization can be found in the CAMPI manuscript:

This visualisation shows per sample (or thus per bar) the distribution of how many peptides are annotated with a specific taxon. I propose to expand this Unipept visualization library with the capability of visualising very generic data that supports this. The input could be an object in the following format:

{
    bars: [
        {
             name: "sample",
             items: [],
             counts: []
        }
    ]
}