Add access to kogito variables from serverless workflow expression

For some particular cases, for example, a REST call which implementation cannot be changed (so passing the information in the HTTP header wont work), it will be nice to provide the process instance id as arg of the REST invocation (this need arises when doing Ansible intergration).

In order to do that, we can mimic the CONSTANT and SECRET approach and add a new custom reserver word, KOGITO, to access this kind of information

rhn-support-zanini wdyt?