'Export as JSON' link missing from reusable blocks

[noisysocks]

From ​https://github.com/WordPress/gutenberg/issues/11275.

Describe the bug

5.0 Beta 2 is missing the 'Export as JSON' link that usually appears underneath reusable blocks.

To Reproduce

Steps to reproduce the behavior:

1. Make a block a reusable block
2. Select "Manage All Reusable Blocks
3. Hover over one of the block titles
4. Look for link "Export as JSON"

Expected behavior

Next to the Edit and Trash links, there should be an 'Export as JSON' link.

[pento]

In 43854:

Blocks: Add "Export as JSON" action to the wp_block post list screen.

Remove the "Quick Edit" for wp_blocks, too, as they don't need any of that functionality.

Props noisysocks.
Fixes #45247.

[SergeyBiryukov]

Reopening for trunk.

[jeremyfelt]

In 44220:

Blocks: Add "Export as JSON" action to the wp_block post list screen.

Remove the "Quick Edit" for wp_blocks, too, as they don't need any of that functionality.

Merges [43854] from the 5.0 branch to trunk.

Props noisysocks.
Fixes #45247.