Blender Git Loki

Outliner: Use operator option to decide which item to rename

The `outliner.item_rename` operator needs to decide if it should rename the
active or the hovered item. Previously it checked if the event is a press
event, which is a hacky way of doing this and limit how the operator can be
used in the keymap.
Now use a operator option to let this be controlled on the keymap level.

Doesn't change any default behavior.