Add folding doc and multiline comments

idea/testData/folding/noCollapse/class.kt

@@ -0,0 +1,4 @@
+class A <fold text='{...}'>{
+    val a = 1
+    val b = 1
+}</fold>

idea/testData/folding/noCollapse/function.kt

@@ -0,0 +1,4 @@
+fun foo() <fold text='{...}'>{
+    val a = 1
+    val b = 1
+}</fold>

idea/testData/folding/noCollapse/imports.kt

@@ -0,0 +1,6 @@
+import <fold text='...'>kotlin.*
+import kotlin.*
+import kotlin.*
+import kotlin.*</fold>
+
+fun foo() {}

idea/testData/folding/noCollapse/kdocComments.kt

@@ -0,0 +1,9 @@
+<fold text='/**...*/'>/**
+ * Kdoc licence
+ */</fold>
+package some
+
+<fold text='/**...*/'>/**
+ * Some Kdoc comment
+ */</fold>
+class A

idea/testData/folding/noCollapse/multilineComments.kt

@@ -0,0 +1,4 @@
+<fold text='/.../'>/*
+ * Some multiline comment
+ */</fold>
+class A

idea/testData/folding/noCollapse/object.kt

@@ -0,0 +1,4 @@
+object A <fold text='{...}'>{
+    val a = 1
+    val b = 1
+}</fold>

idea/testData/folding/noCollapse/oneImport.kt

@@ -0,0 +1,3 @@
+import kotlin.*
+
+fun foo() {}