Add keyset pagination for tags API

What does this MR do and why?

It adds a keyset pagination to Tags API. Additionally it applies a Gitaly pagination to the first page of the results. It should improve the performance of the endpoint when no arguments are provided.

Screenshots or screen recordings

Without pagination

With keyset pagination

How to set up and validate locally

Feature.enable(:tag_list_keyset_pagination)

1. Find repository with tags
2. Send a request to: http://localhost:3000/api/v4/projects/<project_id>/repository/tags
3. Send another request to: http://localhost:3000/api/v4/projects/<project_id>/repository/tags?pagination=keyset&page_token=<tag_name>, where tag_name is a tag from the first request.
4. Verify that you see elements that go after the page token

For example, you have a repository with following tags:

aaa
bbb
ccc
ddd

Then the request to http://localhost:3000/api/v4/projects/<project_id>/repository/tags?pagination=keyset&page_token=bbb should return

ccc
ddd

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.