JLS: add special java client that can execute jls commands

the java language server uses special "java.apply.workspaceEdit"
commands that already contain the workspace edit that should be applied
when triggering the command.

Change-Id: If7c53b9b097aaeca289e3958a39be37a9725d395
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/android/javalanguageserver.h

@@ -41,6 +41,7 @@ public:
     QVariantMap toMap() const final;
     void fromMap(const QVariantMap &map) final;
     LanguageClient::BaseSettings *copy() const final;
+    LanguageClient::Client *createClient(LanguageClient::BaseClientInterface *interface) const final;
 
     QString m_languageServer;
     QString m_workspace;