Add task alias for new gradle wrapper task and related defaulting improvements

Add GRADLEWRAPPER task alias for new simple gradle wrapper task defined in Groovy for Bamboo - see

Provide better defaulting for gradle related tasks defined in Groovy for Bamboo so that they do not need to be explicitly specified on an addTask - these defaults (mostly) correspond to the defaults on the UI

• default script location to FILE

• default test directory option to standardTestDirectory

• default testResultsDirectory to */*reports/.xml,*/*results/.xml,