Block Outline Improvements

[derekblank]

Feedback from @fluiddot testing:

1. In the Quote block, when the citation is selected the block is outlined. This seems unnecessary.
2. In Media blocks, when the caption is selected the block is outlined. This seems unnecessary.
3. Space block is rendering two elements outlined. Probably we could remove the one from the block.
4. Shotcode block already renders the content within a box, seems we could remove the block outline.
5. ~When selecting a social icon, is not clear which is actually selected.~ https://github.com/WordPress/gutenberg/pull/53377
6. ~In the Story block, the upload progress bar is too close to the block outline.~ Story block is no longer available.
7. ~Layout Grid block is not displaying a dashed border for its inner blocks.~ https://github.com/wordpress-mobile/gutenberg-mobile/pull/6014

[geriux]

Updating this with the items already addressed:

• [x] 5. When selecting a social icon, is not clear which is actually selected. https://github.com/WordPress/gutenberg/pull/53377
• [x] 7. Layout Grid block is not displaying a dashed border for its inner blocks. https://github.com/wordpress-mobile/gutenberg-mobile/pull/6014