twap at height NTRN-357

[quasisamurai]

TASK

This is a patched astroport oracle contract with necessary astroport contracts and also some modifications 4 Neutron needs:

• Implemented twap_at_height query
• PERIOD const is now parameter
• implemented simple and complex tests

since the astroport contract has nothing to integrate with at the moment, the tests are implemented directly in the repository (see integration.rs ) discussed w @swelf19

How to test: you don't need to since you're seeing green check mark in this PR

need to recheck smth

[foxpy]

code looks fine, though I am not sure how are we going to resolve dependency hell with cosmwasm-std and cw-X libraries.

[oldremez]

I believe there's a lack of tests with a height between two snapshots. Current tests cover only cases with exactly those blocks at which the oracle was updated. But in a real situation, the queries will be done to the arbitrary block that in general lies between snapshots. And what is the expected behavior here: do we need to return the past TWAP calculated or the next one (since the block we get a query for lies in the period of time for which the next TWAP is calculated, right?).

Also, out of scope but maybe we should have a todo for it: if we keep the history anyway, shouldn't we allow updating at arbitrary blocks? I mean for any block we can find the previous snapshot that is more than the update period far away. Or it will lead to more gas consumption?