Show "lists" palette as separate menu option from "variables"

Tiny request -- I'm making a large project with many, many, many variables and lists. It's not rare for my block palette to look something like this:

(Gif of scrolling the variable, list, and more blocks sections of the palette. Each section takes up considerably more than the full screen height.)

(Admittedly this is in a sprite with a lot of local variables, but you get the idea.)

This puts a bit of a strain on my hand - and just takes a lot of blank time - since I'm often scrolling very far down from the variables section to reach the lists I'm looking for. The "variables" and "lists" sections both having buttons in the block palette, rather than just "variables", would prevent the majority of that.

The counter-argument is that that might draw too much attention to lists, but if that's really a problem, why not make lists into an extension? This would also give them their own separate block palette section and button, and would avoid exposing the feature to new users. (I'm inclined against it, though. Bringing more attention to the lists section, even just by adding the button, would help Scratchers learn more and make more interesting projects, I think... although I suppose you could argue that extensions do the same thing. 🤷‍♀️)

The issue does not name files, tests, or an entry point. Start by locating the block palette implementation and its existing variables section, then determine how a separate lists menu option fits the current palette behavior; done means lists can be opened directly without scrolling through variables.