Feature: Add assist to unwrap tuple declarations

[harudagondi]

Implement #12923 for only tuples.

Does not implement unwrapping for structs, as mentioned in the issue.

Add assist to unwrap tuples declarations to separate declarations.

fn main() {
	$0let (foo, bar, baz) = (1.0, "example", String::new())
}

becomes:

fn main() {
	let foo = 1.0;
	let bar = "example";
	let baz = String::new();
}

Changelog

Feature

• Added assist to unwrap tuple declarations.