Set destination or go back to the edit page after convert

Problem/Motivation

Some entities (especially Media) don't have an entity "View" page. So after converting a single

Steps to reproduce

1. Edit a media entity
2. Click the "Convert Bundle" tab and proceed the conversion
3. After the last conversion step, see "Page not found" error, as there's no "view" page for media by default (and typically)

This is confusing for users who don't know about the technical background. They may thing they broke something with the conversion.

Proposed resolution

Redirect to the entity edit page after single entity conversion finished
Or add a special case for Entity type "Media" to go to the edit page there and otherwise to the entity view page.
Or set a destination parameter on the "Convert Bundle" tab (/media/3173/convertbundles?destination=/media/3173/edit) and store it as redirect target after the conversion

Remaining tasks

1. Discuss which way to go
2. Implement
3. Test
4. Release

User interface changes

API changes

Data model changes