[FE] Render context receivers for functions, properties, and classes

compiler/testData/diagnostics/tests/extensions/contextReceivers/outerClass.txt

@@ -2,7 +2,7 @@ package
 
 public fun f(/*0*/ outer: Outer): kotlin.Unit
 
-public final class Inner {
+context(Outer) public final class Inner {
     public constructor Inner(/*0*/ arg: kotlin.Any)
     public final fun bar(): kotlin.Int
     public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean