Standardized empty states for blocks

[jarekmorawski]

It'd be fantastic to set up a framework for the empty/placeholder states that blocks could tap into. This could help standardize their design and optimize the UX across the editor. There are two types of block empty states I've identified while working on one of the Woo blocks.

Setup. Displayed when a block needs additional user input to display context.

This state has several variations. For instance, it can ask the user about a specific asset, like a product.

Or, like in the Group block, it can let the user choose a starting layout or provide some information.

Missing context. Displayed when a block a custom field or a source the block was previously connected to is no longer available (related to the upcoming Binding API).

I'm sure there are more and I'll gladly help identify them. In a perfect world, block empty states would follow the same design patterns based on use cases: user input, layout selection, errors, missing information, etc.

[gziolo]

There is already <BlockVariationPicker /> that could get some iterations.