feat: carousel back action integrated into browser history

[aegroto]

Description

This is a cleaner version of this PR as that branch contained a lot of commits and was diverging from master.

Carousel's modal now closes when navigating backward through the browser's history, going back to the post instead of returning to the main page. Fixes #1508.

Screenshots

I have committed a version of the fix which works in case of multiple carousel shows as well:

recording.mp4

Additional Context

I wasn't able to use router.push as suggested in the original issue and had to stick to the native APIs, which is documented by NextJS as an alternative to router methods as well.

The code overrides the close function of the carousel, triggering a 'back' navigation when the carousel is closed. It is still relying on native history APIs, unfortunately a router's shallow navigation immediately closes the carousel, presumably due to the listener I have highlighted in the previous comments.

Before marking this PR ready for review I would like to know if it's fine for your to use window's native APIs, then maybe explore a solution which relies on router in the future.

Checklist

Are your changes backwards compatible? Please answer below: Yes

On a scale of 1-10 how well and how have you QA'd this change and any features it might affect? Please answer below: 8, I tested the changes manually and with various content.

For frontend changes: Tested on mobile, light and dark mode? Please answer below: Yes

Did you introduce any new environment variables? If so, call them out explicitly here: No

[aegroto]

@huumn @ekzyis Sorry for the ping but I'd need a feedback on this PR once you've got some time, just to be aware if this solution relying on the direct APIs is fine for you.

[huumn]

We are occupied with high priority issues. We will get to this when we have time.