Remove design-oriented controls from Cover block toolbar while in Write mode

[richtabor]

Description:

When the editor is in Write mode, the Cover block should not display the full screen or matrix controls in its toolbar. These controls are primarily used for layout adjustments, which aren’t relevant in write mode where focus is on content.

Steps to Reproduce:

1. Open the editor and insert a Cover block.
2. Switch the editor to write mode.
3. Observe that the full screen and matrix controls are still visible in the Cover Block toolbar.

Expected:

In write mode, the Cover Block toolbar should only display essential controls related to content, excluding full screen and matrix controls.

Visual:



[up1512001]

@richtabor created PR can you please review it 🙇‍♂
#66853