Add possibilty to, while computing nodes:
add more nodes to the task manager,
edit, duplicate and remove nodes without breaking the tasks that are submitted
* use it in MetadataListView and GraphEditor 'add Node' menu
* GraphEditor: forward MenuItem key events to searchBar to be able to continue editing the filter even if it lost active focus
* allow to solo a 3D media from the GraphEditor by double clicking on a node or an attribute with the Control modifier pressed
* consistent with Viewer3D.MediaLibrary behavior (solo on Ctrl+Click on visibility button)
* handle supported file extensions in Viewer3DSettings
* add a ToolButton for duplicating/removing following nodes in corresponding entries instead of having a separate item
* change text when those button are hovered to reflect the change of action
* wording: rename "Delete Node" to "Remove Node"
* ease the deletion of a branch from a given starting point
* accessible with alt+del on a node
* re-order menu to put the most destructive operation (Clear Data) at the very end
* keep track of currently hovered node in UIGraph on Python side
* Node: show border on hover + make MouseArea contain everything else to always get hover events, even when cursor is over children attribute pins
* fit when the underlying graph has changed (new/open project)
* add 'F' shortcut to fit
* trigger fit after UI has been fully initialized (correct sizes)
* increase EdgeMouseArea thickness for easier picking
* EdgeMouseArea: propagate modifiers on pressed
* increase edge visual thickness when hovered
* add edge contextual menu on right click
* Alt+RighClick shortcut to delete an edge
Handle nodes move and auto-layout on Python side by using GraphLayout and MoveNodeCommand.
* Node QML component relies on underlying core.Node object's position
* MoveNodeCommand is called after a Node has been dragged
* partial/full auto-layout for specific graph operations (Duplication, Augmentation...) are now part of those operations
* serialized position in node data allows to properly restore nodes coordinates on undo/redo
* remove all layout/node moving code from QML
