KT-29926: Support completion of suspend lambda body and parameters

- ^KT-29926 Fixed

idea/idea-completion/testData/handlers/basic/highOrderFunctions/HigherOrderSuspendFunctionWithArgs.kt

@@ -0,0 +1,9 @@
+fun foo(p : suspend (String, Char) -> Boolean){}
+fun foo(p : suspend (String, Boolean) -> Boolean){}
+
+fun main(args: Array<String>) {
+    fo<caret>
+}
+
+// ELEMENT: foo
+// TAIL_TEXT: " { String, Char -> ... } (p: suspend (String, Char) -> Boolean) (<root>)"

idea/idea-completion/testData/handlers/basic/highOrderFunctions/HigherOrderSuspendFunctionWithArgs.kt.after

@@ -0,0 +1,9 @@
+fun foo(p : suspend (String, Char) -> Boolean){}
+fun foo(p : suspend (String, Boolean) -> Boolean){}
+
+fun main(args: Array<String>) {
+    foo { s: String, c: Char -> <caret> }
+}
+
+// ELEMENT: foo
+// TAIL_TEXT: " { String, Char -> ... } (p: suspend (String, Char) -> Boolean) (<root>)"

idea/idea-completion/testData/smart/functionLiterals/SuspendExplicitParameterTypesRequired.kt

@@ -0,0 +1,11 @@
+fun foo(p: suspend (String, Int) -> Unit){}
+fun foo(p: suspend (Char, xx: Any) -> Unit){}
+
+fun bar() {
+    foo(<caret>)
+}
+
+// ABSENT: "{ s, i -> ... }"
+// ABSENT: "{ c, xx -> ... }"
+// EXIST: "{ String, Int -> ... }"
+// EXIST: "{ Char, xx -> ... }"