Extract methods to issue tracker services

What does this MR do?

In !21933 (closed) we re adding Open Project integration to GitLab (which started as a community contribution in gitlab-foss!24888 (closed)). The MR is big and I, therefore, started with creating smaller MRs, this is the first one.

This MR creates support_close_issue? and support_cross_reference? methods on IssueTrackerService with false values and overrides them in JiraService with true. The methods will return true in OpenProjectService, too

Does this MR meet the acceptance criteria?

Conformity

• [-] Changelog entry
• [-] Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• [-] Database guides
• [-] Separation of EE specific content