Filter vector data based on attribute values
User story
As a user, I want to be able to filter my loaded vector data (e.g. shapefile or GeoJSON) based on a chosen attribute value. Ideally, multiple similar vector layers (with same column headers) could be filtered by the same value all at once.
Comments
Currently, attribute values are taken into account only for categorization or classification. Providing further filtering options would require a table view of the layer attributes, e.g. displayed at the bottom of the map. For batch-application of filters to multiple layers, it should first be discussed how exactly the user interface should look like in order to support this. An "Apply to all" button might be sufficient, but errors must be properly handled for layers where the filter cannot be applied.