filter_temporal, filter_bbox, ... on vector cube

[soxofaan]

The filter processes like filter_temporal, filter_bbox, filter_bands, ... currently only accept a raster-cube object as input (first argument), but shouldn't we also support vector cubes as input?

[m-mohr]

Sure, we need to go through all processes and check the data types. But it doesn't help to open issues for all these processes separately now. First we need to get the basics defined, then I'll go through the processes and check each of them on required changes.

Closing as duplicate of #68, #323 and Open-EO/openeo.org#58