add "return to sampler" button

[iTrooz]

You access that button by right-clicking on any node, and it will return to the sampler while expanding the selected node

Future extension of this: highlight (like, a temporary glow effect) the node selected when returning to the sampler

[iTrooz]

@lucko Hello ! Do you have any feedback on my PR ? Thanks :)

[iTrooz]

@lucko Hello ! Is there a chance that this PR gets merged ?
Is there something wrong with the code, or is the feature idea itself problematic ?
I'd love to have some feedback from you, even if its a flat out refusal
Thank you