Fixed de-serialization of MembershipSourceType by letting the JacksonJsonEnumHelper know that the first letter should be capitalized

Actually fetch all the memberships with UserAPI.getMemberships() and also provide a pager based method for lazy fetching

Use case: oauth2 access limited time tokens which should be updated on regular basis. Supplier allows us to move refresh logic outside client.
Use specified setter to set up supplier after gitlab api object creation.

This makes it possible to stream data coming
from another server straight into the POST request to Gitlab,
saving an extra, expensive, and useless IO operation on disk.

Fix #769

The `imported` ActionType was missing from the enum.

Adding branches_to_be_notified to SlackService and deprecating notify_only_default_branch as per
https://docs.gitlab.com/ee/api/services.html#createedit-slack-service

New `action_type` values were recently added in the Events API: `approved`, `accepted`, `opened`, `deleted`.  This change adds the new types to the ActionType enum.

A 'scope' attribute was added to the Events API that allows retrieval of all events for a user across all the projects that user has access to.  This change adds support for this new attribute.

based on docs https://docs.gitlab.com/ee/api/packages.html and inspired by GroupProjectsFilter

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