Constants removal in out signal communication

src/main/java/avatartranslator/AvatarActionOnSignal.java

src/main/java/avatartranslator/AvatarBlock.java

...main/java/avatartranslator/AvatarExpressionAttribute.java

.../avatartranslator/AvatarExpressionAttributeInterface.java

src/main/java/avatartranslator/AvatarExpressionConstant.java

...ava/avatartranslator/modelchecker/AvatarModelChecker.java

ttool/src/test/java/cli/CLIAvatarModelCheckerTest.java

ttool/src/test/resources/cli/input/scriptmodelchecker_val4

.../test/resources/cli/models/CoffeeMachine_Avatar_Async.xml