Add buttons to navigate to next/previous search result in job log page

What does this MR do and why?

Adds buttons to navigate to next/previous search result in job log page

References

#580854 (closed)

Screenshots or screen recordings

Before	After
	VIDEO:

How to set up and validate locally

1. Checkout this branch and run gdk locally
2. Go to any project's pipeline details page eg: http://127.0.0.1:3000/gitlab-org/gitlab-test/-/jobs/152
3. Search the log which has multiple results, notice the next and prev buttons and try using them to navigate and scroll to the result
4. Try resizing browser window to see the scrolling behaviour if log output isn't long enough.