"set featured image" can be misinterpreted

[timse201]

Description

You can set the selected image as a featured image via the drop-down menu. This one should be renamed to "set as featured image". "featured image" alone can be misinterpreted that you will be guided to an interface to select a featured image.
The string is reused in the post side panel to set a desired picture.

Step-by-step reproduction instructions

1. add a new image block
2. upload a new image
3. open the options dropdown menu

Screenshots, screen recording, code snippet

Environment info

• WordPress nightly
• Gutenberg 19.8.0

Please confirm that you have searched existing issues in the repo.

• Yes

Please confirm that you have tested with all plugins deactivated except Gutenberg.

• Yes

Please confirm which theme type you used for testing.

• Block
• Classic
• Hybrid (e.g. classic with theme.json)
• Not sure