Merge pull request #2280 from Activiti/CTI777-2259-Assigning-a-task-through-task-update-does-not-perform-same-checks-as-claim

feat: task assign, update, CandidateUsers add/delete, CandidateGroups add/delete

Merge remote-tracking branch 'origin/CTI777-2259-Assigning-a-task-through-task-update-does-not-perform-same-checks-as-claim' into CTI777-2259-Assigning-a-task-through-task-update-does-not-perform-same-checks-as-claim

Merge pull request #2260 from Activiti/CTI777-2113-Create-new-method-to-expose-subprocess-IDs-to-a-given-process-instance

Implementation of a method subprocesses

Merge branch 'develop' into CTI777-2259-Assigning-a-task-through-task-update-does-not-perform-same-checks-as-claim

* process instance variables initialization
* now handling json vars as json
* poc on variables as json
* make sure engine fully configurable
* turn off java ser ootb

fix(versions): update Activiti/Activiti versions

Merge branch 'develop' into CTI777-2113-Create-new-method-to-expose-subprocess-IDs-to-a-given-process-instance

* process instance variables initialization

* improve exception message

* Add activiti-spring-process-extensions dependency to parent pom

* Fix failing tests

* Fix transitive dependency

* check types of variables on proc start

* Rebasing with develop

* make variable types and their validation extensible

* add test specifically for loading of extensions

* simplify names and add comments

* add slf4j

* feat: add parentProcessInstanceId attribute support for Execution entity

* chore: test parentProcessInstanceId mapping for query with variables

* fix: update javadoc

* fix: remove boilerplate superExection code from IntegrationContextBuilder

* fix: add  parentId conversion in APIProcessInstanceConverter tests

* fix: add missing assertValidProcessInstanceResult assertion

* fix: add missing assert for result description attribute

* Add changes from depending PR

fix(versions): update Activiti/Activiti versions

* fix: (IntegrationContextBuilder) add process instance business key

* fix: add execution context attributes in IntegrationContext in Connector

* chore: remove ExecutionContext class dependency

* fix: extract parentProcessInstanceId from SuperExecution if exists

* fix: handle possible NullPointerException case

* fix: throw ActivitiException if running outside CommandContext

* fix: typo