querier: Add TLS to Thanos APIs

[bwplotka]

Prometheus have this from January, it was added to Alertmanager this week too. I think it's time to add it to Thanos too (:

[roidelapluie]

Feel free to reuse the exporter toolkit if it suits your needs: https://github.com/prometheus/exporter-toolkit

[saswatamcode]

Can I look into this?

[stale]

Hello 👋 Looks like there was no activity on this issue for the last two months.
Do you mind updating us on the status? Is this still reproducible or needed? If yes, just comment on this PR or push a commit. Thanks! 🤗
If there will be no activity in the next two weeks, this issue will be closed (we can always reopen an issue if we need!). Alternatively, use remind command if you wish to be reminded at some point in future.

[stale]

Closing for now as promised, let us know if you need this to be reopened! 🤗