I made a block to add a script to a sprite!
Sadly, though, you can't really directly delete them, because a) a sprite can have multiple of the same script, and b) there would be no way to label and find them without changing the way scripts work altogether. But you can do this.scripts.children = [] which deletes all of the scripts at once (included in the project).
Also, the scripts don't appear in the scripting area right away, but since the purpose of this is to work programmatically, that doesn't really matter. The script is still present in the scripting area, even if you can't see it.
Finally, you need to use @ego-lay_atman-bay's Hat blocks in grey rings for the script to function.
Without further ado, here's a link to the library.