Binding editor: autocomplete using the global scope explorer

[Janpot]

It should be possible to use the global scope tree on the right to fill in values in the code editor.

Notes:

• This should be triggered by an icon button on every tree node. We should leave clicking the node for navigating the tree only
• Can we maintain focus + cursor in the editor while navigating this tree, to make sure the user always knows where code will be inserted?