Twenty Twenty: styles issue in Quote block

[kajalgohel]

In Twenty Twenty Theme, when we add Quote block in editor side, the styles option named Plain is not reflected in front-side and editor-side. Actually the Default Styles and Plain Styles are looking same in both the side.

Steps to replicate:
1: Activate the Twenty Twenty Theme
2: Add Quote block
3: Choose Plain styles option
4: See block at editor side(block is looking same, nothing change)
5: Save Page/Post
6: View the page/post at front side

For better understanding I provide video attachment URL.
Video URL: ​https://share.cleanshot.com/iIXb2WcfmC4un0eapOgG

Thanks

Adding missing styles for block style plain.

Trac ticket: https://core.trac.wordpress.org/ticket/56011

[kajalgohel]

added patch for removing border of Plain styles from Quote block

[costdev]

#57860 was marked as a duplicate.