DIsplaying diff with conflicts should not display a custom choice selection

Right now it's possible to display a diff with the conflicts which happened when trying to merge a document.
The conflict emphasis also provides a select to allow to navigate between the versions of the conflicts, however it also displays a "custom" choice, which is mainly used when this conflict view is used to take a decision.
We should have a way to specify that the view is used for taking a decision, or to just navigate and inform about a conflict.