Add Interchain Name Service CosmWasm contract

[rrrliu]

What is the purpose of the change

This pull request adds a standalone module to Osmosis with a name-service contract. This enables Osmosis addresses and eventually all interchain accounts to be linked to a simple human-readable address, e.g. richard.ibc.

More relevant information in the README — would be great to get thoughts, particularly on the mechanism design.

Brief Changelog

• Adds x/interchain-name-service module with name-service CosmWasm contract
• Methods
  • Register name
  • Adding a bid to a name
  • Accepting a bid for a name (in progress)
  • Removing bid(s) from a name (in progress)
• Queries
  • Resolve from name -> address
  • Reverse resolve from address -> name

Testing and Verifying

This change added tests and can be verified as follows:

• Unit tests at x/interchain-name-service/contracts/name-service/src/integration_tests.rs
• Instructions for manually interacting with contract on LocalOsmosis in x/interchain-name-service/README.md

Documentation and Release Note

• Does this pull request introduce a new feature or user-facing behavior changes? no
• Is a relevant changelog entry added to the Unreleased section in CHANGELOG.md? no
• How is the feature or change documented? x/interchain-name-service/README.md