What problem does this address?

As of Gutenberg 17.3, only a button block supports shadow feature. Add support to more blocks.

What is your proposed solution?

Enable the shadow support to following blocks.

• Button — ready for review in Add effects/box shadow tools to block inspector #57654
• Cover — Ready for Review in Enable shadow support for cover block #61883
• Image
• Group
• Column and Columns

Enable for more blocks based on the feedback.