[AA] Fix getKtExpressionType for augmented array assignment

This previously worked on accident because the get call in an
augmented array assignment wouldn't have a resolved argument list, and
so `argumentsToSubstitutedValueParameters` would return null.
Now, we additionally verify that we're in a `set` call.

#KT-66124

analysis/analysis-api/testData/components/expressionTypeProvider/expressionType/assignment/augmentedArrayAssigment.kt

@@ -0,0 +1,8 @@
+operator fun Array<String>.get(index1: Int, index2: Int) = this[index1 + index2]
+operator fun Array<String>.set(index1: Int, index2: Int, elem: String) {
+    this[index1 + index2] = elem
+}
+
+fun test(s: Array<String>) {
+    <expr>s[2, -2]</expr> += "K"
+}

analysis/analysis-api/testData/components/expressionTypeProvider/expressionType/assignment/augmentedArrayAssigment.txt

@@ -0,0 +1,2 @@
+expression: s[2, -2]
+type: kotlin.String