Playground block: Add option to show the Blueprint (and edit it in the builder)

[adamziel]

It would be useful to have an on/off switch to display the "show the Blueprint used in this block" feature. This way the viewers could review how the example was set up.

[flexseth]

💯

[akirk]

It reminds me of Fork me on Github, it could be a cool way to have people build on an existing playground.