parameter_assignments tests should include destructuring cases

[srawlins]

Child issue of #58837

I think there should be a test case like:

void f(String a, String b) {
  (b, a) = (a, b); // Swap!
}

in which the lint rule would report that assigning to the parameters a and b violates `parameter_assignments.

I think there should also be an identifier pattern case, but I'm not 100% sure it's allowed:

void f(int two) {
  var list = [1, 2, 3];
  var [_, two, _] = list; // Assignment to parameter 'two'.
}