Being able to select multiple blocks columns #9086

When I make projects, I sometimes want to rearrange my script to be more readable, and since I use a lot of custom blocks, my script gets spread out in multiple column.

I so think it would be great if we could select multiple column at once, just like in the costume editor were we can select multiple elements at once.

Here is how I think it should work :

• first the user left click on an empty space, if they hold the click for more than 200ms (it may be customizable, I put 200ms because it's the average human reaction time)
• then they drag the mouse to an other position, every blocks in this area is marked as "selected"
• then, every action that should normally affect only one block / column affect every selected blocks. If the Ctrl key is down and the setting "Grab single block with Ctrl key" is active, the actions like moving the blocks would only affect the selected blocks
• to unselect the blocks, the user would only have to click again on an empty space