This enables the synchronization of Feature Flags to Jira, using the
endpoints described at:

  https://developer.atlassian.com/cloud/jira/software/rest/api-group-feature-flags/#api-featureflags-0-1-bulk-post

When a user has enabled the GitLab application in their Jira project,
feature flags will be associated with Jira issues if the Jira issue keys
are mentioned in the feature flag description.