Enforce -store.max-query-length at query time.

[cyriltovena]

This is related to cortexproject/cortex#2826.

It would be great that we have the check made prior hitting the store so that we can remove the unnecessary check in cortex.

This check should :

• work for all API endpoint (instant,range, labels and series)
• include range queries like rate({foo="bar"}[500d]).
• be done at the frontend and querier level.

/cc @pracucci