[AA] Provide API for obtaining array element type of KtType

KTIJ-23199

analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/components/KtFirTypeProvider.kt

@@ -266,5 +266,10 @@ internal class KtFirTypeProvider(
         }
         return firSymbol.dispatchReceiverType(analysisSession.firSymbolBuilder)
     }
+
+    override fun getArrayElementType(type: KtType): KtType? {
+        require(type is KtFirType)
+        return type.coneType.arrayElementType()?.asKtType()
+    }
 }