In principle we want always the add-on to be disabled. Initially we had a json patch ready that never was used.

Ensure that is disabled by default using directly the configuration of the MCE.

In the current `main` and `4.20`  it is already disabled, so, we have to remove the unnecessary (and confusing) patch. Also the readme should be updated.

In the previous branches `4.19` we also have to disable the addon on the MCE manifest.