New rule: Function paramater should not be nullable

[BraisGabin]

Expected Behavior of the rule

Some times I found functions that allows a null parameter to then assert that it's not null. Those functions shouldn't accept a null parameter, they should force the caller to take the decission to force the non-null or don't cal it.

Non-compilant

fun foo(a: String?) {
  println(a!!)
}

This function should be declared like this:

fun foo(a: String) {
  println(a)
}

Context

This kind of errors are added with the java to kotlin translator. And some times after a few refactor you can end up with code like this.

[severn-everett]

I'll add this in when PR #4379 is integrated, as it looks like it falls within the same purview of that rule.

[cortinico]

Closed by #4431