Introduce "Add '== true'" quick fix for TYPE_MISMATCH

#KT-39930 Fixed

idea/testData/quickfix/addEqEqTrue/notBoolean.kt

@@ -0,0 +1,10 @@
+// "Add '== true'" "false"
+// DISABLE-ERRORS
+class Foo {
+    fun bar() = ""
+}
+
+fun test(foo: Foo?) {
+    if (foo?.bar()<caret>) {
+    }
+}

idea/testData/quickfix/addEqEqTrue/notBoolean2.kt

@@ -0,0 +1,14 @@
+// "Add '== true'" "false"
+// DISABLE-ERRORS
+// ACTION: Add 'toString()' call
+// ACTION: Change parameter 's' type of function 'baz' to 'Boolean?'
+// ACTION: Create function 'baz'
+class Foo {
+    fun bar() = true
+}
+
+fun baz(s: String) {}
+
+fun test(foo: Foo?) {
+    baz(foo?.bar()<caret>)
+}

idea/testData/quickfix/addEqEqTrue/simple.kt

@@ -0,0 +1,9 @@
+// "Add '== true'" "true"
+class Foo {
+    fun bar() = true
+}
+
+fun test(foo: Foo?) {
+    if (foo?.bar()<caret>) {
+    }
+}

idea/testData/quickfix/addEqEqTrue/simple.kt.after

@@ -0,0 +1,9 @@
+// "Add '== true'" "true"
+class Foo {
+    fun bar() = true
+}
+
+fun test(foo: Foo?) {
+    if (foo?.bar() == true) {
+    }
+}

idea/testData/quickfix/addEqEqTrue/simple2.kt

@@ -0,0 +1,10 @@
+// "Add '== true'" "true"
+class Foo {
+    fun bar() = true
+}
+
+fun baz(b: Boolean) {}
+
+fun test(foo: Foo?) {
+    baz(foo?.bar()<caret>)
+}

idea/testData/quickfix/addEqEqTrue/simple2.kt.after

@@ -0,0 +1,10 @@
+// "Add '== true'" "true"
+class Foo {
+    fun bar() = true
+}
+
+fun baz(b: Boolean) {}
+
+fun test(foo: Foo?) {
+    baz(foo?.bar() == true)
+}