Implemented ChatWindow for Project Scope

...rc/main/java/unipotsdam/gf/config/GFRocketChatConfig.java

...rc/main/java/unipotsdam/gf/interfaces/ICommunication.java

...f/modules/communication/service/CommunicationService.java

...c/main/java/unipotsdam/gf/modules/user/HiddenUserTag.java

...rschen/src/main/java/unipotsdam/gf/modules/user/User.java

...en/src/main/java/unipotsdam/gf/modules/user/UserView.java

...in/java/unipotsdam/gf/process/ProjectCreationProcess.java

...schen/src/main/java/unipotsdam/gf/session/GFContexts.java

...schen/src/main/java/unipotsdam/gf/taglibs/ChatWindow.java

...nsamforschen/src/main/webapp/project/js/create-project.js

...orschen/src/main/webapp/project/js/edit-group-settings.js

gemeinsamforschen/src/main/webapp/project/tasks-student.jsp

...samforschen/src/main/webapp/taglibs/gemeinsamForschen.tld

gemeinsamforschen/src/main/webapp/test.html

...dules/communication/service/CommunicationServiceTest.java