Tool for merging Transform nodes

[omichel]

It is often desirable to merge two nested Transform nodes to optimize a world file.
If a Transform node is selected in the scene tree and if it has a parent node which is a Transform node with a single children, then we could display a context menu item entitled "Merge with parent Transform".
Similarly, if a Transform node has a single children which is another Transform node, then we could add a context menu item entitled "Merge with child Transform".
In both case, the result of selecting this menu item would be the actual merge of the two Transform nodes into a single one with the translation, rotation, scale and children fields adapted consequently.

Such a feature would replace the online rotation tool which was used to combine several rotations.