Backport ServiceHook#execute from EE

What does this MR do?

In EE this method takes an additional argument that specifies the name of the hook to trigger. There is no particular reason to not backport this to CE, since by default the behaviour remains the same. By backporting this code we remove the need for prepending ServiceHook with a module in EE.

What are the relevant issue numbers?

https://gitlab.com/gitlab-org/gitlab-ee/issues/8244

Does this MR meet the acceptance criteria?

• Conforms to the code review guidelines
• Conforms to the merge request performance guidelines
• Conforms to the style guides
• Conforms to the database guides