Added a branch with a first draft for logos on ResourcesWidget (see pinned development branch).

• Logos are only available in the v2-API of OLS, so I added a useLegacy-parameter to toggle the API version. Logos are then only shown if useLegacy == false
• For now, logos have their own column in the EuiBasicTable. This is not optimal because some logos (e.g. from Human Disease Ontology) require a higher width to be properly displayed. One approach could be to additionally display the logos, if available, in the "Resource Name" column. However, this makes alphabetical sorting of this column more complicated, and a nice display of both items in one cell is not trivial in EuiBasicTable.

What is your opinion on the current status @jusa3?