[FIR] Require equivalent candidates to have the same parameters order

NB: In general, it's unclear what to do in cases
like the following one, even when sometimes
we could, indeed, prefer something:

```
fun foo(a: Int, b: String, c: Boolean)
fun foo(b: String, c: Boolean, a: Int)

foo(c = false, b = "", a = 0)
```

^KT-55933 Fixed

compiler/testData/diagnostics/tests/ambiguityNamedVararg.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // DIAGNOSTICS: -DEBUG_INFO_MISSING_UNRESOLVED
 // ISSUE: KT-55933