Osmosis price oracle

[uint]

Maybe closes #99

• [x] check for outdated price data in consumer (store timestamp)
• [x] review how/when subscriptions are saved/removed in provider (IBC handshake vs explicit local endpoint?)
• [x] for twap, verify how sdk.Dec gotten from arithmetic_twap_to_now is stringified
• [x] tests

[uint]

Initial review of the price provider. Will take a look at the consumer next.

Hey @maurolacy! I appreciate the review, but there's no need to go so in-depth when this is still a draft, pending a cleanup. I feel like the energy is better spent taking a high level view and verifying if this is what we want. I'll address the comments on Monday. Till then!

[maurolacy]

Thanks for the pointer. Put some comments there as well.

[codecov-commenter]

Codecov Report

Attention: 321 lines in your changes are missing coverage. Please review.

Comparison is base (c20eecc) 88.40% compared to head (1dfb124) 87.18%. Report is 16 commits behind head on main.

Files	Patch %	Lines
contracts/consumer/remote-price-feed/src/ibc.rs	0.00%	105 Missing :warning:
contracts/osmosis-price-provider/src/ibc.rs	0.00%	92 Missing :warning:
...ntracts/consumer/remote-price-feed/src/contract.rs	0.00%	60 Missing :warning:
contracts/osmosis-price-provider/src/contract.rs	0.00%	30 Missing :warning:
contracts/consumer/remote-price-feed/src/msg.rs	0.00%	14 Missing :warning:
...racts/consumer/remote-price-feed/src/bin/schema.rs	0.00%	7 Missing :warning:
...tracts/consumer/remote-price-feed/src/scheduler.rs	92.06%	0 Missing and 5 partials :warning:
contracts/consumer/remote-price-feed/src/state.rs	0.00%	2 Missing :warning:
packages/apis/src/ibc/packet.rs	0.00%	2 Missing :warning:
contracts/consumer/remote-price-feed/src/error.rs	0.00%	1 Missing :warning:
... and 3 more

:exclamation: Your organization needs to install the Codecov GitHub app to enable full functionality.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #155 +/- ## ========================================== - Coverage 88.40% 87.18% -1.22% ========================================== Files 69 80 +11 Lines 13151 14264 +1113 Branches 13151 14264 +1113 ========================================== + Hits 11626 12436 +810 - Misses 992 1310 +318 + Partials 533 518 -15 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.

[uint]

Alright, I won't stall more. I'll try to add some tests in a separate PR for what I can, although there's very little non-IBC logic here.