Split ReplaceSingleLineLetInspection to SimpleRedundantLet & ComplexRedundantLet

Relates to #KT-32010

idea/testData/inspectionsLocal/complexRedundantLet/dotWithComparison.kt

@@ -0,0 +1,6 @@
+// PROBLEM: none
+// WITH_RUNTIME
+
+fun main(args: Array<String>) {
+    args[0].let<caret> { it.isBlank() && it.toByteOrNull() != null }
+}