Block Editor: Filter to hide screen options panel

[aduth]

The block editor introduced in WordPress 5.0 provides its own interface for managing Screen Options documents panels, in the "Options" entry of the menu found in the top-right of the screen.

See:

• ​https://github.com/WordPress/gutenberg/issues/10210
• ​https://github.com/WordPress/gutenberg/pull/10215

The Gutenberg plugin ​adds a filter to avoid having the screen options markup being present on the screen. As best I can discern, an equivalent filter was not added as part of the WordPress 5.0.

In practice, it doesn't cause much an issue, only because Gutenberg's interface overlaps with the positioning of -- and thus obscures -- the Screen Options tab.

Related: ​https://github.com/WordPress/gutenberg/pull/13569

[noisysocks]

In 49040:

Editor: Hide Screen Options tab from block editor

The block editor provides its own interface for managing screen options, so we
can safely hide Screen Options tab found in the top right of the page.

Props aduth.
See #46157.