fix: auto-set block timestamp for historical queries

[JoowonYun]

Effects

• [x] Soft update
• [ ] Breaking change
• [ ] Chain fork related

Major Reviewer

@leeyunseon

Background

When querying the state of CosmWasm, timestamp is the current time.

Summary

This change automatically set's the block time on the Context that is provided to all queries. It does this by querying for the CommitInfo for that particular version/height from the RMS.

Checklist

• [ ] Backward compatible?
• [ ] Test enough in your local environment?
• [ ] Add related test cases?