Fix: Do not remove selected block on document tab

[jorgefilipecosta]

Description

Fixes: #13309

Previously when we selected the document tab on the sidebar the block was unselected, with these changes the block remains selected.

How has this been tested?

I added some block, I selected a block, I toggled the sidebar to the document tab and I verified the block kept selected.

[afercia]

@jorgefilipecosta thanks for looking into this!

I've tried it too, but I'm afraid it's not so simple 🙁 The problem I ran into is that with this approach, the sidebar doesn't switch any longer to Block when clicking on a block.

• click on a block
• the Block tab is selected
• click on the Document tab
• the block stays selected (this is good)
• at this point, click on another block
• the sidebar doesn't switch to Block any longer

The problem is that the switching mechanism expects there's no block selected.

[afercia]

See extended comment.

[afercia]

Note: on the related issue there's some consensus to try a new approach:

would it be possible to store a reference to the "last-selected" block and, when clicking again on the Block tab, restore its selected state?

[gziolo]

@jorgefilipecosta do you plan to revisit this PR or should we close it and let other contributors address it based on the feedback provided by @afercia?

[jorgefilipecosta]

I guess we can close, I will try to revisit soon with an alternative approach.