Add "flip equals" intention for String.equals extension from stdlib

So #KT-19282 Fixed

idea/testData/intentions/swapStringEqualsIgnoreCase/.intention

@@ -0,0 +1 @@
+org.jetbrains.kotlin.idea.intentions.SwapStringEqualsIgnoreCaseIntention

idea/testData/intentions/swapStringEqualsIgnoreCase/equals.kt

@@ -0,0 +1,4 @@
+// IS_APPLICABLE: false
+fun test() {
+    "ABC".equals<caret>("abc")
+}

idea/testData/intentions/swapStringEqualsIgnoreCase/equalsIgnoreCase.kt

@@ -0,0 +1,8 @@
+// WITH_RUNTIME
+fun test() {
+    "ABC".equa<caret>ls(Foo().bar(), ignoreCase = true)
+}
+
+class Foo {
+    fun bar(): String = ""
+}

idea/testData/intentions/swapStringEqualsIgnoreCase/equalsIgnoreCase.kt.after

@@ -0,0 +1,8 @@
+// WITH_RUNTIME
+fun test() {
+    Foo().bar().equa<caret>ls("ABC", ignoreCase = true)
+}
+
+class Foo {
+    fun bar(): String = ""
+}