All sources open as java even when they are not.

Go to definition opens external sources as a .class file. As far as I can tell a file extension can only belong to a single language. In this case .class is related to java? The actual source file that corresponds to the .class file is not always a .java file. I suspect that if the source was opened as a .java, .scala, .clj etc... vscode would give proper syntax highlighting for the source

Environment

• Operating System: OSX 10.14.5
• JDK version: 1.8.0_162
• Visual Studio Code version: 1.36.1
• Java extension version: redhat.java@0.47.0

Steps To Reproduce

1. Include a maven dependency that is not written in java.
2. Go to definition for a class in that dependency.

Here is a sample project includes a scala kafka client. org.sample.app.App declares a SimpleConsumer, F12 on it.
non-java-dep-sources-sample.zip

Current Result

The source opens as a .class file and attempts to use the java syntax highlighting.

Expected Result

I would expect the source to not be assumed as java. With the scala extension installed I would expect scala highlighting to work.
Scala extension: https://marketplace.visualstudio.com/items?itemName=scala-lang.scala

Additional Informations

I did see #786 and it said that the .class extension is working as designed. I see this as a short coming. The .class extension makes sense if you are viewing decompiled code, but not once sources are available.

从外部源的 Go to definition 流程开始，并使用链接的 non-java-dep-sources-sample.zip 项目（包括其 Scala Kafka client）复现该行为。跟踪可用源为何会作为 .class 文件打开，然后验证不再假定源是 Java，并确认已安装的 Scala 扩展可以提供高亮。