Is your feature request related to a problem? Please describe.
The Placeholder component (and other similar components) allow for icon, label, and instructions props, for an "informed" component. InnerBlocksTemplatePicker does not allow for this, as each of the corresponding props are established within the component itself.

It would be useful for blocks to pass custom icon, label, and instructions props, so the template picker can be relative to the current block.

For example, we recently adapted this functionality within the CoBlocks Form block. It works great, but the template placeholder is not relative to the Form block. Without the block icon within the toolbar, you wouldn't know this was a Form block template/pattern selector.

Describe the solution you'd like

If props were available, I would:

1. Use the block's icon, in place of the layout icon currently provided
2. Change "Choose layout" to "Choose form layout"
3. Update the instructions to reference form templates.

These would all make the block's placeholder state much more relative, providing context to the pattern selector.

Describe alternatives you've considered
There are none.