Fix sidebar toggle tooltip

What does this MR do and why?

Fixes an issue where the tooltips are reversed on the issue / MR sidebar toggle buttons

Fixes #422753 (closed)

Screenshots or screen recordings

Buggy behavior:

Issues	MRs
Screen_Recording_2023-09-13_at_6.06.53_PM	Screen_Recording_2023-09-13_at_6.05.29_PM

For MRs, the page has to be loaded with the small viewport. Resizing to the small viewport after loading won't exhibit the same bug.

Note that some expand buttons (on mobile viewport and the MR expand button) do not have has-tooltip so the tooltips look different. They also do not have a default tooltip and the tooltips are only added after toggling. I did not change this behavior in this MR.

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.