Blender Git Loki

Fix Outliner editbone selection with 'Sync Selection'

When editbones were selected from the Outliner (and they were connected
to a parent) with the 'Sync Selection' option turned ON, they could not
get duplicated.

For duplication to work, the (connected) parent bone's tip also has to
be selected [which was not the case when selection is done from the
Outliner under above circumstances]. The reason being that
armature_duplicate_selected_exec ->
ED_armature_edit_sync_selection clears the BONE_ROOTSEL flag if the
parent bone's BONE_TIPSEL is not set.

Caused by rB71eb65328078 btw.

The correct "parent-tip-selection" would actually happen in activation
- `tree_element_active_ebone`
-- `tree_element_active_ebone__sel`
but for 'Sync Selection' this happens [also] in
- `outliner_sync_selection_from_outliner`
-- `outliner_select_sync_to_edit_bone`
which did not do the "flushing" to the parent bone's tip

Now use existing dedicated function for this.

ref. T82347

Reviewers: Zachman

Differential Revision: https://developer.blender.org/D9470