Consider allowing anonymous in-place structures only to suggest a code action to extract one automatically

[novusnota]

Like, so the user can write the following:

asm fun divmod(a: Int, b: Int): {Int, Int} { DIVMOD }

And the language server would suggest to extract it into a standalone definition as Tact currently does not support such in-place structures. Thus, the end result would look like this:

struct DivmodResult {
    _: Int;
    _: Int;
}

asm fun divmod(a: Int, b: Int): DivmodResult { DIVMOD }