Add intention for replacing explicit function literal parameter with 'it'

Kotlin's function literals have a shortcut for one-argument literals:
the single argument doesn't need to be explicitly named, but can be
referred via the 'it' contextual keyword.

For example, 'array(1, 2, 3).filter { x -> x % 2 == 0 }'
          -> 'array(1, 2, 3).filter { it % 2 == 0 }'

Add an intention action for this transformation.

idea/testData/intentions/replaceExplicitFunctionLiteralParamWithIt/applicable_cursofOverParamInInnerLiteral.kt

@@ -0,0 +1,2 @@
+fun foo(a: (Int) -> Int): Int = a(1)
+val x = foo { p -> foo { y -> <caret>p } }

idea/testData/intentions/replaceExplicitFunctionLiteralParamWithIt/applicable_cursofOverParamInInnerLiteral.kt.after

@@ -0,0 +1,2 @@
+fun foo(a: (Int) -> Int): Int = a(1)
+val x = foo { foo { y -> <caret>it } }

idea/testData/intentions/replaceExplicitFunctionLiteralParamWithIt/applicable_cursorOverParameterDeclaration.kt

@@ -0,0 +1,2 @@
+fun applyTwice<A>(f: (A) -> A, x: A) = f(f(x))
+val x = applyTwice({ <caret>x -> 1 + x }, 40)

idea/testData/intentions/replaceExplicitFunctionLiteralParamWithIt/applicable_cursorOverParameterDeclaration.kt.after

@@ -0,0 +1,2 @@
+fun applyTwice<A>(f: (A) -> A, x: A) = f(f(x))
+val x = applyTwice({ <caret>1 + it }, 40)

idea/testData/intentions/replaceExplicitFunctionLiteralParamWithIt/applicable_cursorOverParameterUse.kt

@@ -0,0 +1,2 @@
+fun applyTwice<A>(f: (A) -> A, x: A) = f(f(x))
+val x = applyTwice({ x -> <caret>x + 1 }, 40)

idea/testData/intentions/replaceExplicitFunctionLiteralParamWithIt/applicable_cursorOverParameterUse.kt.after

@@ -0,0 +1,2 @@
+fun applyTwice<A>(f: (A) -> A, x: A) = f(f(x))
+val x = applyTwice({ <caret>it + 1 }, 40)

idea/testData/intentions/replaceExplicitFunctionLiteralParamWithIt/applicable_formatsProperly.kt

@@ -0,0 +1,6 @@
+fun foo(i: (Int) -> Unit) {}
+fun test() {
+    foo { <caret>x ->
+        array(1, 2, 3).filter { x -> x % 2 == 0 }
+    }
+}

idea/testData/intentions/replaceExplicitFunctionLiteralParamWithIt/applicable_formatsProperly.kt.after

@@ -0,0 +1,6 @@
+fun foo(i: (Int) -> Unit) {}
+fun test() {
+    foo {
+        <caret>array(1, 2, 3).filter { x -> x % 2 == 0 }
+    }
+}

idea/testData/intentions/replaceExplicitFunctionLiteralParamWithIt/notApplicable_alreadyUsesImplicitIt.kt

@@ -0,0 +1,4 @@
+// IS_APPLICABLE: false
+
+fun applyTwice<A>(f: (A) -> A, x: A) = f(f(x))
+val x = applyTwice({ i<caret>t + 1 }, 40)

idea/testData/intentions/replaceExplicitFunctionLiteralParamWithIt/notApplicable_hasMultipleParameters.kt

@@ -0,0 +1,4 @@
+// IS_APPLICABLE: false
+
+fun call2(f: (Int, Int) -> Int, x: Int, y: Int) = f(x, y)
+val foo = call2({ <caret>x, y -> x + y }, 40, 2)

idea/testData/intentions/replaceExplicitFunctionLiteralParamWithIt/notApplicable_notFunctionLiteralParameter.kt

@@ -0,0 +1,8 @@
+// IS_APPLICABLE: false
+
+val foo = { (x: Int) ->
+    class Inner() {
+      fun temp(<caret>y: Int) : Int { return x + y }
+    }
+    Inner()
+}

idea/testData/intentions/replaceExplicitFunctionLiteralParamWithIt/notApplicable_parameterHasExplicitType.kt

@@ -0,0 +1,2 @@
+// IS_APPLICABLE: false
+val incr = { (<caret>x: Int) -> x + 1}