Fixed the description text of block movers for horizontal movement on multiple selection

[thisissandip]

Fixes #25158

Description

The description text of the blocks which can be moved horizontally was not correct on multiple selection.
Refer #25158

How has this been tested?

1. Select a block that can be moved horizontally (eg. Buttons Block)
2. Add 2 to 3 blocks to move them around
3. Select multiple blocks
4. Inspect the block mover buttons
5. The correct descriptive text should be displayed according to the orientation of the blocks

Screenshots

Types of changes

Bug fix

Checklist:

• My code is tested.
• My code follows the WordPress code style.
• My code follows the accessibility standards.
• I've tested my changes with keyboard and screen readers.
• My code has proper inline documentation.
• I've included developer documentation if appropriate.

[t-hamano]

I would like to test this PR based on bug scrubs.
It needs to be rebased first, but it will work fine 👍

[t-hamano]

Hi @thisissandip,

I needed your PR to reflect the latest trunk, so I imported your branch into gutenberg repository and created a new PR.
Therefore, I would like to close this PR.

Also, the unit tests failed and I would like to resolve that in the new PR.

Of course, your credit is also reflected in the commit.

I appreciate your contribution 😄

[thisissandip]

Thanks for taking over @t-hamano!