refactor step definitions

src/main/resources/REST/json/Policy.json

...st/java/api/test/rest/tsa/cache/CacheStepDefinitions.java

.../java/api/test/rest/tsa/policy/PolicyStepDefinitions.java

...test/java/api/test/rest/tsa/task/TaskStepDefinitions.java

src/test/resources/features/tsa/cache/v1/cache/GET.feature

src/test/resources/features/tsa/cache/v1/cache/POST.feature

...y/policy/{group}/{name}/{version}/evaluation/POST.feature

...olicy/policy/{group}/{name}/{version}/lock/DELETE.feature

.../policy/policy/{group}/{name}/{version}/lock/POST.feature

...esources/features/tsa/task/v1/task/{taskName}/GET.feature

...sources/features/tsa/task/v1/task/{taskName}/POST.feature