BBB: limit publish and delete action for recordings only to recordings of type presentation

Some BBB instances create recordings with different types. E.g. a "presentation" (default) and in addition also a "download" or "podcast". This information is encoded into the recording type. 

Unfortunately BBB handles those recording types not independently. E.g. it is not possible to just delete the "download" but keep the "presentation". The delete API works on the recording ID which includes all recording types. 

In OpenOlat this can lead to confusion as the delete action is in the row for each recording type, but actually deletes both items without warning. 

The solution is to offer the the publish and delete action only for recording rows of type "presentation". The presentation is always there, but download and podcasts are optional. This way the publication and delete process becomes more transparent.