Request: add "rename" to sprite right-click menu in Sprite Corral

[rmunn]

Currently, sprites can be renamed in the field at the top of the view:

But it would be nice if they could also be renamed by right-clicking on them in the Sprite Corral.

In other words, I'd like this menu:

to look something like this:

I've noticed a lot of "Sprite(2)" and "Sprite(3)" (... and even "Sprite(15)" and worse ...) in Snap! projects I've looked at in the Explore tab on the website. It seems like many Snap! beginners don't discover that sprites can be renamed. Adding a rename option to the right-click menu would likely help the discoverability of this feature.

[rmunn]

Relevant to this request: #2222

When sprites are renamed, whether via a "rename" menu or by typing a new name into the field at the top, any dropdowns referencing that sprite should automatically be updated to the sprite's new name: see #2222 (comment)

[rmunn]

A more advanced version of this request would be that when a new sprite is created, the rename dialog would pop up automatically, to give it a new name. The current behavior, where the name is "Sprite(2)" (or even, if "Sprite(2)" is duplicated, "Sprite(2)(2)") is automatically created, could be kept insofar as that autogenerated name could be the default in the dialog box (starting out selected so that typing will automatically delete the existing text and replace it).

In other words, when a new sprite is created (whether by clicking the "New turtle sprite" button or by clicking the paint button), it would be good to prompt the user to name the new sprite. If the user truly doesn't care about the name, they can just press Enter and the "Sprite(2)" name will be accepted. But this would go a long way towards teaching beginners to give their sprites meaningful names.

We emphasize meaningful names for new blocks (functions), so it would be good to emphasize meaningful names for new sprites (objects) as well.