Clearify diagnostic messages that involve internal visibilities

KT-7354 Fixed

Visibility.displayText is deprecated with warning.
Diagnostics for java visibilities changed.

core/descriptors.jvm/src/org/jetbrains/kotlin/load/java/JavaVisibilities.java

@@ -47,10 +47,16 @@ public class JavaVisibilities {
 
         @NotNull
         @Override
-        public String getDisplayName() {
+        public String getInternalDisplayName() {
             return "public/*package*/";
         }
 
+        @NotNull
+        @Override
+        public String getExternalDisplayName() {
+            return "package-private";
+        }
+
         @NotNull
         @Override
         public Visibility normalize() {
@@ -78,10 +84,16 @@ public class JavaVisibilities {
 
         @NotNull
         @Override
-        public String getDisplayName() {
+        public String getInternalDisplayName() {
             return "protected/*protected static*/";
         }
 
+        @NotNull
+        @Override
+        public String getExternalDisplayName() {
+            return "protected";
+        }
+
         @NotNull
         @Override
         public Visibility normalize() {
@@ -111,10 +123,16 @@ public class JavaVisibilities {
 
         @NotNull
         @Override
-        public String getDisplayName() {
+        public String getInternalDisplayName() {
             return "protected/*protected and package*/";
         }
 
+        @NotNull
+        @Override
+        public String getExternalDisplayName() {
+            return "protected";
+        }
+
         @NotNull
         @Override
         public Visibility normalize() {