[JENKINS-61683] Initial implementation of GitLab Hook parameters as env variable (#86)

* Initial implementation of GitLab Hook parameters as env variable

* Remove event classes from serialization

* Add push hook env variables

* Add Tag push data

* Add all webhook payload to variables and add documentation

* more docs

* Replace HOOK prefix with GITLAB

* Some reformatting to docs

* Improve docs and add env variables for only WorkflowRun Builds

* Fix ci and add demo test file

* fix deps

* Add more mr event env variables

* Remove test

Author: baymac

.gitignore

@@ -7,3 +7,4 @@ target
 .project
 .settings
 bin
+.DS_Store