IDEA-126595 provide completion variants for Charset.forName()

java/java-tests/testData/codeInsight/completion/normal/CharsetName.java

@@ -0,0 +1,7 @@
+import java.nio.charset.Charset;
+
+public final class FileAttributes {
+  {
+    Charset.forName("utf<caret>")
+  }
+}