[6.x] Fix recache token leaking into pagination links

[lazerg]

With background recache enabled, pages rendered by a recache request emitted pagination links containing the __recache token, and that HTML got written to the static cache, so the token was served to everyone until the page was regenerated by an ordinary request.

The paginator's withQueryString() appended the raw request query string, token included. It also bypassed Laravel's Paginator::queryStringResolver(), so the usual way of filtering pagination query params never got called. It now goes through the resolver and drops the recache token.

Fixes #15294

[lazerg]

The red Windows shard is Tests\UpdateScripts\UpdateGlobalVariablesTest, which asserts the order of the sites array. That order comes from the Stache index, and nothing here touches it. The remaining Windows shards show as failed because fail-fast cancelled them.

[duncanmcclean]

I've just re-ran the Windows tests and they seem to be passing now. I've opened #15298 to fix the flakey test.