GUACAMOLE-1594: Update all Java and JavaScript dependencies to latest compatible.

NOTE: Several WebPack plugins could not be updated as all plugins within
WebPack's "webpack-contrib" have dropped support for WebPack v4
entirely, but Closure Compiler only supports WebPack v4.

doc/licenses/slf4j-api-2.0.3/README

@@ -0,0 +1,8 @@
+Simple Logging Facade for Java (http://slf4j.org/)
+--------------------------------------------------
+
+    Version: 2.0.3
+    From: 'QOS.ch Sàrl' (http://qos.ch/)
+    License(s):
+        MIT (bundled/slf4j-api-2.0.3/LICENSE.txt)
+