Search: "Recent searches" does not consider different versions

[humitos]

It seems the "Recent searches" shows all the searches performed in the domain. However, in the same domain there could be different versions and even different projects when using subprojects.

We should save the project.slug and version.slug in the recent searches data to know if they match when restoring them from the cache.

How to reproduce:

1. go to https://test-builds.readthedocs.io/en/latest/
2. search for "configuration"
3. click on the result
4. go to a different version using the flyout
5. click on the search input from the flyout

At this point, you will see the "Recent search" you perform in a different version. If you click there, you will go to the other version.

[zanderle]

Yeah, I did not consider this at all. On it.