Draft: Reintroduce published flag for content groups and add modes for live use cases
The publishingMode NONE has been replaced with a separate flag. While technically, the mode is not relevant when a group is not published, with a separate flag the previous mode can be restored when toggling.
This partially reverts changes from 73da43b2077e8594c5ad400d78cc74854ab50d4f.
The publishing mode now also reflects, if a live use case is active.
Modes for live use cases are suffixed with _LIVE
For non-live use cases, only publishing of all and and a range of contents is relevant. For live use cases, Publishing of a range and single publishing is relevant.
Closes: #257, #258
Related: !773 (merged), particify/dev/common-concerns#69
Edited by Daniel Gerhardt