FIR IDE: Add visibility checks to the completion

Visibility checks currently do not work in some cases, for example:

- public nested class of private class is seen globally
- private_for_this does not work
- some other cases I am not yet aware of

If `FirVisibilityChecker.isVisible` fix those issues, they will be fixed
automatically in the completion

idea/idea-completion/testData/basic/multifile/NotImportedExtensionProperty/NotImportedExtensionProperty.dependency.kt

@@ -3,4 +3,6 @@ package abc
 val String.helloProp1: Int get() = 1
 val String.helloProp2: Int get() = 2
 val Int.helloProp3: Int get() = 3
-val helloProp4: Int = 4
+val helloProp4: Int = 4
+
+private val String.helloPropPrivate get() = 1

idea/idea-completion/testData/basic/multifile/NotImportedExtensionProperty/NotImportedExtensionProperty.kt

@@ -1,3 +1,4 @@
+// FIR_COMPARISON
 package first
 
 fun firstFun() {
@@ -5,8 +6,9 @@ fun firstFun() {
     a.hello<caret>
 }
 
-// EXIST: { lookupString: "helloProp1", attributes: "bold" }
-// EXIST: { lookupString: "helloProp2", attributes: "bold" }
+// EXIST: helloProp1
+// EXIST: helloProp2
 // ABSENT: helloProp3
 // ABSENT: helloProp4
+// ABSENT: helloPropPrivate
 // NOTHING_ELSE