Added missing name attribute to Badges class. Also aligned indent of Badges class with rest of api.model package

https://docs.gitlab.com/ee/api/discussions.html#delete-a-merge-request-thread-note

In GitLab 11.11, the Project Hook Key for wiki events was wiki_events.
We don't support GitLab 11.X. We only support GitLab 12.9.2+.
In new version of GitLab the correct key is wiki_page_events.

Since the removal of "X-Total-Pages" and "X-Total" headers, all paginations use the kaminari counter.
In this mode, kaminari counter is reset to -1 during the call of the last page. This part is correct.
Then when we call the `current()` method of the pager to get the current page. This method call the same `page` method than the `next` method. In this method the pager check if there is element before checking if we call for the current page. It throws NoSuchElementException erroneously.

To fix, I change the check sequence. First I check ifthe user call the current page. If so, we return the corresponding items. If not we check if there is such elements and call the API.

- readme_url
- can_create_merge_request_in
- import_status
- ci_default_git_depth
- remove_source_branch_after_merge
- auto_devops_enabled
- auto_devops_deploy_strategy
- auto_devops_enabled
- statistics.packages_size
- shared_with_groups.group_full_path

fix #613 #632 #667

On gitlab.com I got 
```
org.gitlab4j.api.models.AccessLevel forValue
WARNING: [5] is not a valid GitLab access level.
```
so I've added that enum here

Added option to preserve underscores in the JacksonJsonEnumHelper to fix TargetType.MERGE_REQUEST value. (#615)