Refactoring

[Clashsoft]

• [x] There are many uses of control statements without braces, which is a warning and discouraged. Please fix.
• [x] #84
• [x] The ControllerUtil.isController method actually checks if the given object is a Controller OR a Component. It should be named more aptly isControllerOrComponent. In addition, an actual isController method should be added. This example could benefit greatly: https://github.com/fujaba/fulibFx/blob/4264510d39eb8543d995a6ae74e8464a8746e536/framework/src/main/java/org/fulib/fx/controller/ControllerManager.java#L196-L199
• [x] This is a stream that only ever processes a single element: https://github.com/fujaba/fulibFx/blob/4264510d39eb8543d995a6ae74e8464a8746e536/framework/src/main/java/org/fulib/fx/controller/ControllerManager.java#L414-L431 Please simplify.
• [x] This stream would be more readable as a simple forEach lambda that does not require Pairs. https://github.com/fujaba/fulibFx/blob/4264510d39eb8543d995a6ae74e8464a8746e536/framework/src/main/java/org/fulib/fx/controller/ControllerManager.java#L314-L328
• [x] This supposed utility method has side effects in the filter lambda: https://github.com/fujaba/fulibFx/blob/4264510d39eb8543d995a6ae74e8464a8746e536/framework/src/main/java/org/fulib/fx/controller/ControllerManager.java#L442-L450 Please put the warning into a more appropriate place where it is not printed every time the method is called.